Waldorf's Knappability Scale Comparison

[JackCrafty]

In D.C. Waldorf's book "The Art of Flintknapping", he has a list of lithic resources that he rates on a scale of 1 through 5 (page 13).  He says this scale is based on Callahan's scale (Callahan 1979:16) where glass is a 1 and rhyolite is a 5.  Since my scale is reversed and goes from 0 through 10, I have expanded Waldorf's scale to compare it with mine.

Waldorf uses the term "workability" rather than "knappability".

He places many of the materials much lower or higher than I would, which means that my scale (when I add the names of the materials) will be very different.  I will take his ratings into account, though.




Note:  "HT" means Heat Treated.

[TRACY]

I looked at the scale this weekend. I agree on some chert being ranked a little less knappable than my experience with some rock. Kentucky hornstone and Indiana hornstone are fairly equal in my book. Cobden is also the same as hornstone from my experience.


Tracy

[caveman2533]

I find the true flint one ranked so high to be interesting. I have always found good English flint to be hard as heck.

[JackCrafty]

The definition of flint actually puts it in a sub-category of chert.  It occurs as nodules in chalk and has a very fine texture with a waxy, glass-like surface when fractured.  The way I understand it, there are many varieties of flint but "true" flint would be the very best in terms of knappability.  There are some incredible artifacts made from it in France and Denmark, for example.  But I might drop the classification and just stick with "Exceptional-grade chert".

I agree that English flint is very tough (the dark stuff).  All the pieces I've tried would be in the low-grade chert category.

[JackCrafty]

I think I should add that I've been knapping samples of rock found at Native American sites and the majority of the stones (that are in the blank and preform stages) are in the "high-grade chert" category.  I've knapped a couple pieces that might be considered "exceptional-grade" and some that were terrible (two or three that were obviously damaged by heat and one that was extremely tough).  I have yet to knap a preform that felt heat treated but that's probably because those pieces were knapped to completion.

I haven't knapped any finished pieces and I don't plan to.  I think the finished pieces are too valuable and it just doesn't feel right to ruin them.