In a self-published, local archeology book, a much respected collector and amatuer archeologist refers to an adze he found as made of "impure calcareous chert" that was "chipped and ground." He goes on to say the local acidic soils have leached out the calcium carbonate impurities, leaving the adze very light in weight, and light in color. I have held a similar piece found in the same area of Cayuga County, NY, and in fact, it is light as balsa wood and more 'blonde' in color than the normal gray Onondaga Chert color! Quite remarkable. It's surface looks to me like large 'chips' or 'flakes' were wacked out of it during its manufacture. It does not have the overall, smooth surface look of other adzes and celts I have seen.
So while I can understand the "calcium carbonate impurities leached out by acidic soils" part, I'm not sure I understand the "chipped and ground chert" assertion.
Can chert be "ground" ....like hardstone tools are "pecked and ground?" So, wet sand (....assuming this was the abrasive used....) is hard enough to grind down chert to make the bit end of an adze? I thought that the quartz component of sand and chert were of the same hardness. (Moh's = 7)
Any clarification is appreciated!
So while I can understand the "calcium carbonate impurities leached out by acidic soils" part, I'm not sure I understand the "chipped and ground chert" assertion.
Can chert be "ground" ....like hardstone tools are "pecked and ground?" So, wet sand (....assuming this was the abrasive used....) is hard enough to grind down chert to make the bit end of an adze? I thought that the quartz component of sand and chert were of the same hardness. (Moh's = 7)
Any clarification is appreciated!
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