i agree with almost all of your comment. just a few minor points:
- there was a 'chalcolithic' period of copper tools in most places before the advent of bronze, but i believe that bronze tools were already in use in egypt when drilling started
- later investigations did not find emery dust in the oldest drill holes, leading to the conclusion that the abrasive was quartz, so although the egyptians certainly could have been importing abrasives from naxos, they don't seem to have done so until much later
- the identification of plato's 'adamas' with an osmium-iridium alloy is quite dubious; he was certainly talking about a metal, but it could easily have been steel or meteoric iron
- just to clarify, you probably know this, but corundum dust and emery are the same thing (the article was fairly confusing on this point)
- there was a 'chalcolithic' period of copper tools in most places before the advent of bronze, but i believe that bronze tools were already in use in egypt when drilling started
- later investigations did not find emery dust in the oldest drill holes, leading to the conclusion that the abrasive was quartz, so although the egyptians certainly could have been importing abrasives from naxos, they don't seem to have done so until much later
- the identification of plato's 'adamas' with an osmium-iridium alloy is quite dubious; he was certainly talking about a metal, but it could easily have been steel or meteoric iron
- just to clarify, you probably know this, but corundum dust and emery are the same thing (the article was fairly confusing on this point)