<HTML>Sandy J. Perkins wrote:
>I think the question is: How do we get these tools to
>cut a single groove that can be traced around a granite core
>for a length of five rotations, equal to three feet? Please
>explain.
Primary reference for this claim of a single groove of 5 rotations around the surface of the core?
I have no idea how it was made...
However, since the hardest mineral in granite is quartz and it is only about 11% the hardness of natural diamond (the rest of the minerals are all less that about 8% the hardness of diamond), there is not really a problem scratching it now is there? Remember, there is a difference between rock hardness and mineral hardness i.e. they are 2 different properties of the rock. Remember as well, that Miss Morris's claim that an abrasive similar to synthetic diamond with thousand's of pounds of pressure on the cutting bit is needed to cut quartz fails to address the fact that quartz can be easily scratched with a tungsten carbide scriber (similar in hardness to corundum at about 28% that of diamond) and the force generated by one's arm.
I have already pointed out to you that Stocks (2001) produced striation in granite with quartz abrasive. Quartz abrasive grains stuck in copper hand-powered lapidary tools can scratch granite in a single stroke. Since you obviously have studied this object in some detail, maybe you can present the evidence that distinguishes this striation with a particular stage in the manufacturing of the core? What I am looking for obviously, is what evidence are you using to directly associated the striation with the feed-rate of the cutting tool...
Archae Solenhofen (solenhofen@hotmail.com)
Stocks, D.A. (2001) Testing Ancient Egyptian Granite-Working Methods in Aswan. Upper Egypt, Antiquity, 75, 89-94.
>Sandy</HTML>
