10 Pcs Diamond Burr - 1/8'' Shank Long Cone Shape Diamond Burs Bead Reamer for Rotary Tools

Works very well in turquoise I did not try it on any other stone so I can’t say how it would work.

Pointy boys help ream out small holes! Works great

Don't do something dumb like put them in a drill press. Take it slow they cut a good clean hole. Make sure to back out often and i prefer to drill submerged in water to prevent binding gummy materials like surfite. I have used them for surfite and agate. A drill press will apply too much force, i used my foredom.

I used these to remove a broken tap in an engine block. Took the entire kit, but i was able to remove the tap and not damage the engine block.

Drill through a agate like butter… put them on my dremel and they didn’t break

Worked as I expected

I bought these to drill small holes in glass ornaments. I have a drill press for this purpose. The first one I tried had the tip break off. The second one never made more than a tiny divot before bending to the point of being unusable. I found another product that works much better.

These are the best things ever. The points are perfect for reaming. I use these to drill as well, mostly resin/clay. If a piece breaks, it'll still be useful, so nothing goes to waste.