Brainstorming beads

Shell beads from DjRw-14.  Note the interior diameters of less than one millimetre.  Picture courtesy of Terry Clark.  Click to enlarge.

Shell beads from DjRw-14. Large grid is one centimetre, small is one millimetre.  Note the interior diameters of less than one millimetre.   Picture courtesy of Dr. Terry Clark, CMC. Click to enlarge.

The previous post on the remarkable bead-rich burials in shíshálh territory generated a great discussion including contributions from some of the project leaders.  It’d be good to continue that discussion!  But one additional point, as Jesse Morin notes in those comments, and as one of the project leaders Terry Clark raised in an email to me, is the question of, quite simply, how are all these beads getting made?  As you can see in the picture above, these shell beads have a hole diameter of less than one millimetre.  Terry describes some of the holes being not much larger than a human hair!

Detail of above picture, courtesy of Terry Clark. Small squares are 1mm.

We did in face discuss this, ahem, boring issue at some length on this blog in the comments section of this post.  The crux of the issue is, every single one of these beads must have been drilled.  And yet, the kinds of micro-drills required are essentially unknown from the south coast of British Columbia.  So, where are the drills?

Some of the points raised in the previous post comments include:

  • nephrite drills are very unlikely
  • misclassified bone points, some of which which are actually drills — possible, testable – yet why not noticed yet?
  • wooden drill bits (you laugh but it’s possible if abrasive slurry movement was the proximal means of drilling)
  • some other organic drill bit (e.g., bird teeth, fish teeth, etc)
  • pressure flaked micro-drills (but where are they? cf. Chumash micro-drills, which are hyperabundant)
  • sea urchin spines?  Someone has already written a thesis on this topic and they don’t work.  Or do they?
  • drift iron (possible, but 4,000 BP examples are less likely to be iron, of course)

Surprisingly, we didn’t resolve the question in the previous comments section.  But I do think it is worth thinking and talking about this some more.  Some kind of tool was used to make hundreds of thousands of sub-mm holes in shell and stone.  Is it, as Jesse suggests, a kind of craft specialization highly concentrated in space at sites as yet unknown?   Is it the result of use of as-yet-unknown technology, especially non-durable technology? Feather drills, anyone?

Future lines of inquiry that occur to me include:

  • experimental programmes to define the art of the possible.  Can one perhaps punch a hole through?  The picture above clearly shows mostly bi-conical holes.  However, I’ve also seen a lot with very cylindrical holes.
  • more literature review is needed, per Jim’s comment in the previous thread.  This should come from NW Coast but also globally.
  • can either the shell or the stone in these beads be sourced or characterized to isolate raw material distributions?  What’s the state of the possible in this regard?
  • the beads are not just drilled with tiny holes, they are usually (in my experience), extremely flat.  What kinds of shell are they mad from that allows for this?  Are they also ground on their faces?
  • dating a random sample of, say, 10 of the Sechelt beads would be interesting to see if they tightly cluster in time or (perhaps unlikely) they represent several centuries worth of bead making/accumulation.

Small bead manufacture is a several thousand year long tradition in the Gulf of Georgia.  It seems remarkable we know so little about these tiny artifacts with such a large story to tell.  One place to start is with how these beads were made; we also need insight too into how they were worn (blankets? robes?  hair?). Answers to these would promote understanding into how they were deposited, and both of these questions might then also lay a firmer platform for whether we should indeed be interpreting them as evidence for “cultural complexity.”

So brainstorm time, in the comments, everyone welcome!

57 responses to “Brainstorming beads

  1. Must admit when I first saw the picture I though somebody had tipped their Cheerios all over the paper. (doh!)


  2. I am thinking of a post-doc involving bead production in the Gulf of Georgia! Any takers? Just thought I’d throw that out there.

    As Terry indicated, DjRw-14 is full of surprises – not the least of which being the tiniest shell beads (some of them fall through our 2mm lab screens in complete form). There are shell beads of (at least) three different size classes and the stone beads from the first two burials do not have the same mean size. We have undertaken precise measurements of these beads and I am working to expand the database to include beads from many other sites and burials, and I believe this is a crucial first step to learn about bead making as standardized or localized and explore ideas of exchange.

    This potential project (Beads of the Salish Sea or BOSS project (title courtesy of Bryn Letham)) could include beads from all periods; the ones we have found from later contexts elsewhere in shishalh territory are quite different (usually better or less expediently made, fewer of them too (but not from burials either)).

    It is remarkable that neither at DjRw-14 nor anywhere else has there been any smoking-gun evidence found for bead making. However, the type of stone and, especially the shell, are relatively soft materials and I don’t think wooden or non-preserving organic tools are out of the question. Nonetheless, moving beyond comparisons of bead assemblages and into manufacturing technology will certainly require other more sciencey techniques. Perhaps the species of shellfish used for the shell beads could be known through chemical composition; as for the “siltstone” used for the ground stone beads at DjRw-14, we have found that there is little agreement amongst the archaeologists we have talked to regarding sourcing the raw material (or even telling whether two beads are from the same general source area). I know very little about geology, unfortunately. I’m pretty good with shellfish.

    If you are going to be in Honoloulu in April and are interested, I will be presenting a paper along with Danielle MacDonald (a Near Eastern archaeology PhD candidate at U of T – but she has worked in Rupert!) where we attempt to use scanning microscopy to identify different topographic patterns on some the DjRw-14 beads, possibly related to their manufacture.

    Thanks to Quentin and everyone who was involved in the previous post and (hopefully) this one as well. To paraphrase Dylan: I’ve had a head full of ideas that were driving me insane; it is nice to get some of them out there.


  3. Just to throw out an idea – could some of the really small holes be “natural” – it is not uncommon to find shell on the beach with holes drilled by predators (snails mostly I think) and some of these holes are very small. A possible starting point for a bead made around the hole?
    And another idea, does shell hash ever sort out into small flat pieces of about the right size for making beads? I can see this happening, given the way that streams and beaches can sort out same-size flat pebbles. If so, it might be a source for shell bead blanks in very large numbers that could reduce the manufacturing time considerably.
    I have not looked at enough shell beads closely to know if these are even possible.


  4. Stephen — those would be pretty stale cheerios mixed with Captain Crunch, in effect.

    David — is there any funding for a post-Doc? yeah, it’d be a great project. It’s inescapable that at times, beads were produced in hyperabundance yet we have only a rudimentary understanding of how, and a really crude notion of why.

    Yeah, I know Danielle — when she left the lab here it was like someone turned off a 1000 watt bulb!! Looking forward to hearing more. Maybe you can sneak preview an image or something.

    To be pedantic, I guess these beads have three strongly defining characteristics which might help structure thinking. These are broadly true regardless if stone or shell:
    – they tend to be parallel faced
    – they tend to be round in plan
    – they have a hole in the middle.

    The first speaks to raw material choice — but it would be great to know how much face grinding there is on these, if any.

    The second requires a lot of work to achieve — the classic example illustrated by Hillary Stewart is to take a bunch of drilled, rough beads and string them like lifesavers and then grind them all together along the edge. Plausible but where/what is the evidence? Lots of grinding stones, and a few examples of slate chunks with section marks/drill holes (I guess — never seen one in person).

    The hole is the most confounding of all, since we have no evidence of how the holes were drilled. I think one conceptual or gestural thing to keep in mind is, were the holes drilled into the shell, or was the shell rotated on the drill? To me, the latter is plausible.

    All must consider that the beads are very small in all dimensions and would be hard to handle as individual artifacts.

    APM — that’s a good thought. Some species like rock scallop often have little vesicular holes on the shell. Starfish and moon snails leave pretty large holes, and probably not biconical (excepting Alien scenarios of inside-out drilling!). The shell hash idea is intriguing considering my question of whether the drill turns or the shell turns on the drill. Should be some evidence of waterworn surfaces or edges if this was routine at all.

    I rather doubt that shale/slate can be sourced geochemically, but would be open to thoughts on that. Jesse Morin’s NIR tool is very fast and relatively cheap, but the very nature of these sedimentary and meta-sedimentary rocks seems to be a poor candidate for precise geochemistry.

    An isotopic signature of shellfish seems plausible, but at the same time, the whole Gulf is one big sloppy growth medium for the shellfish, so, I’d want to see a working hypothesis of how that would happen. Different bays have different muds and gravels and this defines shellfish isotopes? I know there are shellfish isotope people out there who might be able to quickly reject this idea or tweak it productively.


  5. Duncan McLaren kindly sent the following picture from a publication he has in preparation. It shows Grant Keddie at the RBCM making stone beads using a quartz crystal tipped drill, as well as apparently working nephrite with a “graver” I suppose one would call it.

    Grant Keddie using quartz crystal drill.

    Some quartz crystals I’ve seen in cave deposits are tiny and absolutely suited to making a sub-mm hole. Handling, hafting, and using such a tiny drill would be a challenge. The picture seems to show a drill that would be larger than many NW Coast beads. Nonetheless it is a great picture and makes concrete some of the discussion points here.


  6. Hi
    Good comments all around. My bet is that wooden and bone drills would not work at all – someone may want to try it out but i doubt it. I think microdrills made of quartz crystal microblades would be amongst the most durable types of drills for making so many beads. That being said i’ve never seen one on the NWC or heard of one being reported.

    RE: bead raw materials. NIR (near-infrared) works very well on these to determine their mineralogy. Indeed it can distinguish shell, bone, antler etc. I have run a small sample of beads from Glenrose using this technology. From what i have seen, most are made of 2 different types of clay minerals, and a single odd ball one (mistakenly described as nephrite) was made of some other mineral that i can’t remember. I am in the works of planning a further mineralogical study on a sample of beads from the lower mainland dating to ~5000 BP. In short, NIR works for determining the mineralogy of these very well, is extremely rapid, and is non-destructive. Mineralogical ID is the key first step in any sourcing program. As I was taught and often repeat, you need to separate your apples from your oranges from your bananas first, before you can charge ahead and find out where the apples were grown. If the metaphor isn’t clear, I can explain in boring detail later…


  7. someone please try dogfish skin wrapped over sharpened yew (maybe Dale Croes knows of some who’ve already tried it) I love the Hoko volumes for those experimental archaeological images btw


  8. In regards to rotating the shell on an immobile bit, my initial reaction is one of scepticism. It strikes me that drilling these tiny holes the hard, brittle material is akin to cutting hard stuff with a dremel: you don’t need a lot of pressure, or even a particularly hard bit (if you’ve got cheap spares), but you would benefit a great deal from having relatively high RPM. The fast revolutions can’t be achieved hand-holding the shell or bead, but you can get your bit spinning quite nicely using a setup similar to a fire drill (pump, bow, or just hand-powered). In fact, small spindle whorls could possibly have acted as a sort of flywheel for the drill too.

    What I wonder about is whether it’s faster and easier to drill or to cut. Ostensibly, making stone beads on a flat blank (as pictured in your response, Quentin) means drilling every individual bead, cutting every individual bead out, and then grinding every bead (maybe on a string, but that seems awkward). Necessary for shell beads, but perhaps stone bead makers could streamline the process a bit. How’s this for an alternate sequence:
    1) grind a thicker, cylindrical-ish piece of stone (like ~1cm diameter, 3cm long maybe?) to the desired diameter and cross-section.
    2) drill one hole, end-to-end (or one from each end if that’s your thing).
    3) Slice the sucker up and call it a day. Of course, this would likely result in a lot of ambiguous, cylindrical “bead preforms” showing up at bead manufacturing stations (the enigmatic “whatsit”?). Depending on the consistency of the preform’s cross-section and the thickness of the saw, one may be able to match beads up with their erstwhile neighbours and maybe even see common striation patterns from the abrader (like matching up bullets with the gun that shot them). Evidence against this technique would be if most of the beads have holes coming from both sides, meeting in the middle. Or if the flat surfaces were more patinated or cortexy than the sides.

    As far as identifying the drill material goes, it might be worthwhile getting in touch with Mark Kenoyer at U. Wisconsin, or Zhichun Jing at UBC. They’ve been doing some work with using dental-casting putty to get imprints of Indus Valley and Chinese bead holes and then looking at them under a scanning electron microscope. Pretty good results too. Check out Kenoyer 1997 “Trade and Technology of the Indus Valley: New Insights from Harappa, Pakistan” (World Archaeology) for an example.


  9. We actually have had Mark Kennoyer have a look at them when he was at U of T last year. He was suitably impressed with the shell beads. His questions (like a lot of us) are where are the workshops? And how were these made?


  10. Excellent discussions, and great to once again see so much action on this blog. Much of this discussion reminds me of a fieldschool I was on about 15 years ago (!?!?) in South Africa. We were excavating a small, iron age (I think) settlement site. One of the things we found a ton of was ground ostrich eggshell beads. Very similar in size and form to the stone beads discussed here, though perhaps more analogous to the shell beads in terms of raw material characteristics. Anyways, I seem to recall discussions about them having been smoothed and rounded by stringing them and grinding them in bulk. I actually bought a modern version of a ostrich eggshell bead necklace, which I still have somewhere, though the beads were far more crudely manufactured than those we had been finding archaeologically. Anyways, I have no specific references to offer for this, but suspect that there would perhaps be some great cross-cultural ethnographic and/or archaeological comparisons or analogies to be made my looking at the literature for places like that. Probably similar examples from all over the place.


  11. Hi, look at the shell bead approximately center of the figure above (on the graph paper – zoomed in version), just about right on the cross hairs of the thicker ‘cm’ lines. Note that the bead has two concavities on its lower portion. To me, these look like they were drilled holes as well. So perhaps the production sequence is 1) drill the holes, 2) saw out the beads, 3) string them together and grind a ‘batch’ into a nice round shape. I’m sure a detailed microscopic description of a sample of these would go a long way to sorting this out.
    Nick, I am dubious about the drilling of particularly long beads then segmenting them into shorter ones. It is exponentially more difficult to drill deep very narrow holes than shallow ones. I do remember Mark Kenoyer talking about some very long carnelian beads drilled with copper needle-like drills. But those were exceptional compared to most as they were much more difficult to make.



    • The stone beads at DjRw-14 were certainly biconically drilled. I agree with Jesse on the shell bead chaîne opératoire; and microscopy is being done as we speak (more or less). How exactly they were drilled and with what still remains the big question, especially for the tiny shell beads. The lack of a suitable artifact/tool for this indicates that it may have been perishable. A (hardened) wood or bone splinter would work and the site is lousy with split deer long bones (though none are mm thick splinters). How ’bout it?


  12. It’s a good picture when zoomed in, and shows that many of the holes are bowl-shaped in cross-section with the hole more or less in centre of bowl. That suggest they were drilled with a fairly blunt (rounded) ended drill bit of some kind and perhaps there was a secondary tip on the bit which punctured first when the second side was drilled – or that they were punched through when thin enough to not risk the whole disc.

    They definitely look individually drilled, and few look as if they might have a cylindrical hole of the kind you would get if drilling a long rod prior to cutting. I also think that cutting a perforated rod would have a higher failure rate too, with the disc weakened by the hole. Something for the experimenters to try I suppose.
    I am not sure why I think this, but I believe that Joanna Casey’s MA 1987 at SFU may have had some shell bead manufacturing information in it from the Ohio area. It is not on-line to the likes of me, but maybe someone with better library access can look and see. If I am wrong, then my apologies for a wild goose chase. I do remember her giving us some shells from that area that had many holes drilled in them for extracting button discs, in the 1800 or 1900’s and for commercial reasons.


    • And the little nicks out of the edges that Jesse points out are the kinds of things you would expect if the discs are being drilled out of the surface of a shell with slight overlapping for some discs with older holes. You might even want a bit of overlap, not only to make the most of the shell, but to reduce the cutting effort with a bit of overlap of a previous cut edge.

      Drilling out the discs would be very well suited to the bird bone drills discussed higher up that Becky Wigen first recognised in faunal bags. They would produce relatively flat edged discs, of a common diameter and could be quite speedy. They are quite similar in principle to some kinds of drill bits one can get these days for large hole cutting – a saw tooth edge around a cylinder. They are a bitch to get the cut disc out of, but would not be if you could get in the opposite end to poke it free.


  13. The bird bone drill would be the right diameter for the small shell disc beads (pictured above) but there are also 1000s of shell disc beads with diametres greater than 5 mm, up to 10 mm, which would require a big bird’s (or Big Bird’s?) bones. Most of these larger ones are quite round (unlike the stone beads) and were very likely were shaped after being sawn or perhaps snapped into suitable pieces. With regards to the hole in shell beads, I would imagine that whatever they were strung upon would wear the hole smoother than it was originally, however it may have been drilled. I am sure these beads had a high attrition during manufacture.


  14. Just one note about some observations of the beads from DhRp-52:
    1. The square beads are smaller than the circular beads; if square beads are the preforms, then why are they smaller?
    2. The material is very soft. They probably are a slate material, but we often discussed them as a mudstone. The geologist on site referred to them as “semi-vitrious clay”
    3. If they are being made from quartz crystal, we had plenty of that on site, but not raw material (unworked material).



  15. Edit: not From Quartz Crystal, but with quartz crystal drills….


  16. Also, has anyone used a pump drill in their experiments?


  17. why is there a north arrow in the picture?


  18. Glad to see the North Arrow–must mean the site is up north….

    I like Al Mackie’s idea about taking advantage of Piddock clams and possibly domesticating them (?) to drill (I am sure you meant natural gathering of the results of their fine work–do a Goggle on these clams to see images of their use by artists). They do love shale.

    I found Q’s use of Grant’s experiments (a 1st class experimental archaeologists–someone should draw his attention to this brainstorming!). His use of end-hafted quartz crystals to drill is fascinating. We did find end-hafted microblades at Hoko wet site–split cedar wooden handle, binding and crystal–and never tried this use idea for these in our experimental archaeology–Jeff Flenniken discussed the manufacture of quartz crystal microblades in his dissertation on Hoko microliths, but not uses. To see our examples go to and look at pictures for “Hafted Microblades”

    The one Hoko long tubular coal bead we found is no doubt bi-conically drilled, but this one is so long it would have been hard to do with a quartz crystal bit, though not impossible. This bead (and most of our beads) are illustrated under “Lithic artifacts” and slide “MUP000191” and so polished you could see your image on the surface.

    So I bet we need to look at quartz crystals a “bit” more. Sarah Campbell has a student doing experimental work with some Locarno Beach phase site examples of quartz crystal microblades–maybe he can try this. Thanks, Dale


  19. Adam N. Rorabaugh

    The discussion on bead preforms does make me wonder if some of the slate, schist, and nephrite “rods” seen in some Fraser Delta and Gulf Islands sites might actually be the initial stage of bead production. More or less taking a long piece, continually grinding the facets down to the intended dimensions, drilling through it, and then more or less slicing it into individual beads.

    As for the use of bird bone, I do recall at 45WH1 Cherry Point activity areas with high frequencies of worked bird bone reported in a poster from NWAC a few years ago but you’d have to check with Dr. Campbell on the specifics. These areas also, if I recall correctly, had higher frequencies of quartz crystal microblades. It may be the case that nearly all of the production sequences described here were in use to differing degrees by different embedded craft specialists to produce beads? I’m not certain if micromorph studies could distinguish between different production techniques but it could be the case that multiple, independent, practices for bead production were employed in the area.

    Everything here is pure speculation on my part, but discussions like these to have a better grasp on the labor behind objects being used as indicators of social inequality seem pretty crucial.


  20. good ideas Adam but I don’t think so.
    1) i don’t think nephrite rods exist – see my dissertation:
    – i could be wrong on this but i looked high an low and found none. Also there are no nephrite beads – at least all the ones described as nephrite i analyzed were other materials.
    2) in the slate rods the bedding plane of the slate runs the length of the rod as with the beads. If the rods were sliced up and then drilled this would run across the grain/bedding plane of the slate and would be really tricky…

    I really think folks need to sort out exactly what these beads are made of and what forms that raw material occurs in in nature.


    • I could imagine a variation on Scott’s and Nick’s idea whereby a rod-like preform was formed, then sectioned into disk bead preforms, and then drilled. But problems with this include:
      – the across the grain issue you note would still be in play, at least for beads made of bedded materials
      – there would be an added level of trickiness in drilling the tiny preforms with tiny holes. Sort of like watchmaking-style precision and control needed. Some sort of jig would help.
      – and, this model doesn’t explain the shell bead manufacture where the rod preform is not possible.
      I should start a spreadsheet with ideas that have been considered and rejected!


    • Adam N. Rorabaugh

      Thanks for the correction, material misidentification as you mentioned is a major issue. For instance, when looking at collections of “slate” tools in older collections I’ve found that a portion are in fact ground basalts, dacites, and andesites. Proper material classification is going to be essential towards working out issues of production and consumption in a wide range of technologies, but I’m obviously preaching to the choir here

      As for slate rods, as you said the bedding planes with slate and schist would make it problematic, and probably unlikely.


  21. I will XRF any of these if anyone wants. Its better and higher resolution than NIR that Jessie proposes as it goes beyond simple mineralogy and examines actual element to element composition. Send me stuff people, I have the lab and the technology!


  22. this article provides some descriptive typology for stages of shell bead manufacture but is focused on California and on Olivella shells which isnt that interesting…


  23. For all the doubters of NIR technology, please browse some of the titles in the Journal of Near Infrared Spectroscopy:

    And note: a minimum of 500 NIR publications per year from 1995-present, peaking at 3500 publications in the year 1997. I don’t have access to the numbers for XRF but would be interested to see them.

    XRF and NIR are different tools for different purposes. Better?


  24. Any chance any of the beads could be fired clay? Might be easier to make smaller holes prior to firing…. Or are there striations in the biconical holes?


  25. Lots of great ideas floating out here, thanks everyone. Also, some bead manufacturing ideas are still floating out at the other post comments, so check that once in a while.

    A few impressions from my end:

    – the softness of the material noted by Emily (and Nicole’s idea, which I actually doubt, of fired clay (known on the Columbia I think) but perhaps, unfired clay or fire-hardened clay vs fired) – anyway, softness of material makes a big difference. Are clam shells actually softer than most of the rock types used for these beads? Mussel shell, in my experience, is actually very resistant to abrasion. So basic parameters of the raw materials used should be identified and catalogued.

    – hence the need for some kind of raw material identification. I’ll let the XRF vs NIR folks duke it out — or maybe we need a sort of Iron-Chef-Geochem zap-off. It seems to me though that before we need sourcing, we need basic rock type characterization — is the stuff actually slate? Or shale? Or siltstone? Or semi-vitreous clay? Or hornfels, as I’ve heard suggested?

    – It seems to me that the larger the blank-tablet (whether shell or stone), the less likely the holes are to be biconically drilled. There is less need, and, it is much harder to line the holes up in the middle of a large shell or slab.

    – many beads don’t show biconical drilling but show a fairly finished looking cylindrical interior diameter. This gives a good maximum size on the shaft of the tool used to make them (vs a larger tool with a tiny bit, think key-shaped or like a graver)

    – you know, in my garden, I have a bunch of Douglas fir firewood and a pile of roofing slates. I’m pre-adapted for some testing of the wooden drill bit idea. (I also have deer in my garden which I would rather were a pile of bony raw material). This would mean changing out of my pyjamas though….


    • Interesting that you say that many beads don’t show biconical drilling because the picture in this post shows almost exclusively biconical drilling (what are the chances that they are drilled only from one side and all of them have ended same side up?). Maybe this is a temporal or regional thing as well – statistical analysis would work very well on that one.

      I remember digging a bit of fired clay at St. Mungo in 1981 – it was a small ball of clay, less than 1cm, that had been carefully rolled into a sphere and then apparently pushed against a square edge of some kind prior to firing – maybe got stuck on a bit of wood. I interpreted it at the time as an accidental firing – someones idle fiddling with clay getting into the fire, but who knows. Unfortunately in those days, as is perhaps still the case, the technicians in the museum that processed incoming collections would discard objects they did not believe to be artifacts (manuports spring to mind) so I can’t guarantee that object would be found in the collection now.

      I’m still in my pyjamas too, I could come over, as is, and we could just get into that pile of slate tiles, regardless of clothing.


  26. Hi again, yes, establishing the material type is key especially since the chemical composition of some rock types can overlap depending on what major and minor elements are considered. While possible to establish material type chemically, it’d be really cool to thin section some of the beads if a few could be sacrificed. That would allow for a clear look at the mineralogy to establish rock type and supplement the chemistry, and could potentially help determine if there has been any thermal alteration (as questionable as that may be …but interesting find at St. Mungo APM!). Thanks for the great posts everyone! Looking forward the hearing the fate of the slate roofing tiles:)


  27. This is somewhat related in topic: It concerns drill holes that aren’t biconical for the simple reason that a tube was used to create the holes. I have a personal database with some 37,000 artifact images; part of this includes images of atlatl weights from the U.S. with holes drilled through them by using lengths of cane. The working end appears to have been dipped in a fine sand abrasive and then the tubes were used (presumably with a bow or pump drill). Some of the images I have show incomplete holes — the hole is a reverse doughnut – a ring with the centre intact. Anyone who wants to see any of these, please e-mail me ( Copies of the database are free on DVD for the asking. It would take about 11,000 pages to actually print out.


    • Hi Mike, that is interesting. What is the evidence they were using cane to drill the holes? On the NWC there are quite a few archaeological examples of bird bone tubes used this same way (referenced by various people above). They are thought to have been used for drilling wood and do create cylindrical holes in experimental work. No real reason they could not be used on stone with an abrasive.
      It would be interesting if there were sufficiently hard, natural tubes in the NWC plant world for similar use.


  28. If the source of the clay/stone/sedimentary beads — or a similar material –could be determined I might suggest an experiement: prepare a “sheet” by grinding it flat. Then soak it in water. Then perforate it as required. Water-saturation might make this kind of material less like to crack/break and might present a softer material to be drilled. Could make bone/wood drill bits very feasible. Just a thought.


  29. Just one observation (don’t know if it is helpful):

    What I would do if I wanted to manufacture something like these beads:
    First create the hole.
    And then, after the hole is created, cut out the bead.

    Other than that, it would be good to have some macro-/microscopic images from both sides, maybe some surface characterization (e.g. are there signs of chipping on one side, but not the other?), or even 3D images.


  30. @Emily Wilkerson
    The square beads are smaller than the circular beads; if square beads are the preforms, then why are they smaller?

    Because the square beads that were found today, were too small to be ground into the circular form.

    All the larger square beads (the preforms suitable for further processing) were ground into circular beads.


  31. And as to taking a rod, drilling a sub-1-mm hole (what? 3 cm long?) and then slicing it: Have you ever tried to do that with modern tools, modern drill bits and freehand?

    While I have no strong opinion on how the holes were drilled (the quartz drill seems interesting), here’s what I would do:

    1. Drill holes.
    2. Cut out squares.
    3. Take all squares large enough and sort them roughly by size (smallest distance from hole to edge)
    4. Put all squares of similar size on one string.
    5. Grind squares to circle form.

    The difficult bit is figuring out how to drill the holes, but I think with the quartz drills it should be manageable. Cutting out the squares to be similar and regular is a challenge too, but should be manageable as well. I’d imagine the rest to be simply a matter of invested time.


    • Thanks for your comment Tony. I do think the idea of stringing square beads then grinding them round is a commonly-held belief, albeit without much evidence — even experimental evidence. It’s pictured in the “lifesavers” comment above which has a picture of Grant making some (larger) beads in this manner.


  32. One more thought:

    I think for some beads in the photo you can see hints of the pre-grind square preform.


  33. Maybe this has been covered? If you have 330,000 mostly stone beads strung on a “robe,” has anyone figured out how much this garment would weigh? I wonder if a person could carry such a heavy “robe”? Must be a heavy piece of textile? I possibly missed this angle of consideration? Thanks, Dale


    • Good question, Dale. Obviously if each bead weighs, say, one gram then the “robe” weighs 330kg. One tenth of a gram each is still a hard-to-imagine 33 kgs.

      At some point then you might be talking about a specifically funerary robe, meant to be heavy. Sort of like a personal cairn made out of tiny tiny stones, eh, Darcy?


  34. Volumes of such beads are said to have been revealed at the famously under-reported Hill site on Saltspring Island, DfRu 4. As they’re not particularly attractive, perhaps the weight & labour intensiveness is justified as a pre-columbian Kevlar for high value targets.
    experimental tests for projectile resistance might be interesting.


  35. Just a quick bit of input about drill types. If any of the shale/slate/mudstone beads were drilled with an abrasive slurry, then a very soft bit must have been used. Any hard drill bit would function to push an abrasive slurry away from the intended target. A soft bit, however, would grip the abrasive, and the slurry would provide the lubricant neccessary for such an operation to work properly. So I’m thinking that bird bones, hard woods, urchin spines, or hafted quartz crystals, etc would not work with the slurry method. A better alternative would be soft wood which is very easily obtained, and bits could be cheaply shaped and replaced as needed. Grit would become imbedded in the soft medium and pushed through the stone, not away from it. I imagine a pump drill and a soft bit could be used to produce a huge quantity of beads relatively quickly.


  36. And a beer to any one who can make a reasonable reproduction of those beads using a wood or bone drill!!! There was some talk a little while back here about Q trying this out…

    This mudstone/slate is so soft that no abrasive should be necessary as long as the drill itself is harder than the mudstone/slate. FYI, when the Chinese used traditional techniques (ie preindustrial) to saw or drill nephrite jade, they used iron tools with garnet sand as an abrasive. The iron tools still held the abrasive well enough to get the job done. And nephrite is a 6.5 on the Moh scale (just below quartz) and is the toughest naturally occurring material in the world.


    • Wow, that’s great to know Jesse, thanks for the info. It’s interesting to me that you mention garnet, as my dad, who is a mechanical whiz but has very little knowledge about archaeology, suggested this possibility, but it slipped into the back of my mind. I hope to have the time to start some drilling experiments soon, I would love to take you up on that beer!


  37. Hi Curtis, Jesse — thanks for your comments. I guess it just needs to be experimented on. Somehow I can’t drag my ass around to doing it. I think like a lot of things there would be surprises when actually replicating stuff and I would definitely not write drills made of wood off just yet.


  38. I agree with Curtis Dean. great point! On another note, I have Thousands of site specific beads from BC, Washington, Oregon and California and many are one of a kind and decorated. Several of the very nice ones are made from black Steatite and were collected at the Bead patch Site on the Columbia during the early 1950’s. Anyone wanting to see them for study purposes is welcome to contact me anytime. Jesse you never ever did get back with me about the Glenrose material? Its to bad… Also If you think drilling beads was interesting and a challenge, how about the prehistoric manufacturing and drilling of the long Tube and Wine glass style pipes!

    I have found this topic here on beads extremely interesting as i have always been fascinated with Beads right up to and including the trade beads that were used here in the Northwest during the Fur Trade. Guess thats what happens when one finds a Stone Glenrose Bead on a beach at the age 10. 🙂


  39. The holes are very biconical in the hundreds I saw in a quick visit at the U of T lab, though not apparent in photos above. Having stuck pointy flakes in soapstone and wood and twirled them around by hand and with bow drills, the holes look pretty well like what I’d expect from just using flakes. There are lots of tough knappable rocks out there, especially in coastal BC. Anything approaching obsidian would be too brittle. I think you could hold a bead preform, drill through both sides in a few seconds by hand, and go on quite mindlessly for a while, grabbing a new pointy bit as you need to. The circumferences are very often irregular, sometimes a bit of chattering appears on the edges, and again it makes sense in one way if each bead was formed with an edge of the same flake that was used to drill it. If you’ve ever done repetitive crafty things, I’m betting it’s kind of like that. Years ago I punched a lot of holes in leather “preforms” for purses, belts, and wallets and it’s amazing what you can do in a few hours when the motor habit sets in, until you cramp up. Will be interesting to see what some experimentation reveals. If we’re talking status items, maybe the individual’s slaves were put to work at this. Hmmm … students.


    • OK, but the volume of beads being found would indicate that they are not “repetitive crafty things”, but were likely produced as a specialized craft. We are actually looking at many many person-years of labour, possibly in the thousands of person-years just for the beads we’ve found in the Gulf of Georgia region alone. Hand twisting will not work on this scale. Hand twisting biconical holes in stone beads will work for a day or two. I guarantee if you tried using this motion for 8 hrs a day your wrist would be completely immobile by the end of the week. That is why I advocate that a machine was used, and I do argue for a pump drill even considering their lack of visibility in the archaeological record (although we do have a number of stone discs which could possibly have functioned as fly wheels). I will be replicating drilling methods and will be testing the speed of pump drilling vs bow drilling and hand drilling. The reason I’m thinking pump drills and not bow drills is that in my limited experiments with both techniques, bow drills are not quite precise enough to drill a small, 1mm hole, the bit tends to jump around more than with a pump drill.


      • And I must apologize for some erroneous information, but I meant to write “possibly in the HUNDREDS of person-years” when scribing my earlier comment…I was thinking about two different things while I was writing it. I like the idea of a jig, Quentin, it makes sense. As for the drilling mechanism, I suppose I could be wrong about the hand drilling, which I admit is based on my own personal physical limitations, but I don’t think hand strength fits into the equation. A lot of strength isn’t required, it’s stamina that I think is the limiting factor, and I just think that twisting your wrist is such an unnatural motion that joint pathology would result. As an example, pitchers in baseball use a twisting motion in the wrist to throw curveballs, and those who use the pitch regularly over long careers exhibit morphological changes in their wrists. I’m not sure if hand-powered drilling would be accomplished by using a screwdriver motion or by rubbing a shaft between the palms as illustrated in Duncan McLaren’s experiments, but I think experimentation will unlock these secrets. I just think that efficiency in terms of time would have been important, especially considering the volume of artifacts we are discussing, and whatever method (hand drilling vs pump drilling) is the fastest needs to be taken into consideration. Fun discussion!


  40. I wonder whether we should somehow write off bow-drills on principle considering no Bow and Arrow 4000 years ago when these beads start getting produced in bewildering quantities.

    Mad Dog’s comment also brings back up the question of, where are the distinctive stone drill bits? It’s possible they’re right in front of just waiting for a microscope to be taken to smaller debitage, but, I doubt it — they would have got noticed by now if they were being used to mass produce beads. I do think that we shouldn’t underestimate the hand strength of these people. Couldn’t Crabtree flute a Folsom point by squeezing it in his hand? I think of those fur trappers carrying 200 pounds of Furs over the Rockies walking 30 miles a day — it’s a point on which a sort of naive empathy for physical abilities might do us no good.

    Tony – I agree the long cylindrical holes are an order of magnitude more difficult and require special explanation well beyond the little biconical holes. (Many of which are subsequently finished to make the biconical hole completely cylindrical or almost so)

    I wonder if mass production is easier to envision if we think of the use of a jig of some kind — maybe something made of wood pre-drilled with holes to guide a slender drillbit onto a slate table prior to sectioning — like a cribbage board as jig. Makes me wonder about the “partly finished” slate tablets with their holes but unsectioned i.e. they are jigs – a jig would seem to speed up the process and minimize wastage of raw material.


  41. Curtis, let me know how this goes for you. That beer is still on the table for your efforts.


  42. Yup can’t wait to see what experiments show, and I am in line with Quentin’s point about physical abilities, we assume a lot, and we are wimps. BTW, Eugene Gryba flutes Folsom points by hand, Crabtree never did. See Plains Anthropologist paper. Eugene also presses off 7 cm long “microblades” by hand holding a 3 in long piece of antler in a cloth or thin leather wrap. And about flake drill bits, they’d be broken little tips and snapped flakes, maybe unrecognizable. And then there’s the southern coastal California “microblade” industry, which are retouched bladelets used to drill shell.


  43. maybe these the center openening is a natural hole what kind of shell,? and the outer shaved or sanded.


  44. Elka Weinstein

    Ancient Ecuadorian peoples (3000 B.C.) made thousands of these shell beads, now scattered over beaches throughout. I haven’t seen any published articles specifically about bead-making but I think there are several (in Spanish) on shell jewelry in general.


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