The references to the mining of chert intrigues me (and not because of
the previous string concerning the "mining" of non-mineral substances -
let's let that topic die an honourable death). In the Sullivan Mine we
had pockets of chert rock as well as areas where chunks of chert had
mixed into the waste rock (mainly quartzite) when it was still
sediments. Chert was always a problem for drillers, because the chert
was second only to diamond for hardness (We were told that a diamond
drill bit set with chert had drilled twenty feet into the quartzite).
The chert in the quartzite caused drill bits to run and wore the guage
off them quickly. Drilling in the first stope in which I worked
required much practice to develope a high level of skill (working with a
miner who was an expert). While I can imagine a number of uses for the
material, I would wonder how it could be worked.
North American Indians used this material to make arrowheads and
other cutting tools. Our chert looked like glass and chipped like
glass, so that the natives were able to work it quite nicely.
One person said on this page that it was used in pottery
making. If anyone knows, I would appreciate being told what it is used
for in pottery making and how it is prepared for use.
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