As an old rockhound the idea is fascinating but I would have some reservations about stone scales. I would be concerned about dropping them and breaking them. Unless they are very thick they would be fragile. Also fashioning them would be a real labor of love. Your breakage percentage will be high and you need the right lap wheels to polish them right. Of course if its a hobby thing and you just want to make a few you have my endorsement. Keep us informed.

Oh yes diamond drills. Any lapidary source should carry them as would many jewelry supply houses. Off hand you might check Otto Frei and also the tool shop at Timezone.com which I believe is Frei and Borel