Drilling Agate for Jewelry: Tips & Techniques

Question
Hi Peter:
Have an Agate about 1/8" thick and about 3" long. Would like to drill a small hole in one end to use as a necklace. Do I use a diamond tipped drill or ?
Thanks, Art

Answer
HI ART,

YOU CAN USE A DIAMOND TIP DRILL, BUT AT LOW SPEED AND WITH MUCH CARE. IT WOULD BEASIER TO USE A CORUNDUM TIP ALSO AT LOW SPEED. BEST DRILL SLOWLY WITH A WATER DRIP SO AS NOT TO GET TO HOT. AGATE HAS A HARDNESS FOR AROUND 5 AND OF COURSE DIAMOND IS 10 AND CORUNDUM 9. JUST PRACTISE ON A SCRAP PIECE TO GET THE FEEL OF THE DRILL SO YOU DON'T BREAK THE STONE.

PETER