My kid is obsessed with the Stonekeeper graphic novel series by Kazu Kibuishi. The protagonist Emily has a magic amulet. After unsuccessfully searching the interwebs to buy my kid one, I decided to make her one. Aka Just-in-time Christmas gifting.
I bought some rose quartz pendants. I used Inkscape to mock up the amulet design. Then I engraved it in 2 passes 350speed/100 power at 340 lpi. Then again at 350speed/70% power at 450 lpi.
When it came out it was clearly engraved, but kinda rough. Some roughness is because the curve of the stone I figure, but mostly because it’s quartz I’m guessing? So I used some acrylic paint to darken the engraving. I’m not a great painter - this kind of detail stuff is not my cup of tea. But I think the kid will like the darkened look better. (I also painted the back of the stone pink to make it more pink when light shines through.) When the paint dries, I’ll spray a sealer on it.
I’m thinking I might try again with scoring, because now that I look closer at the graphic novel, it is more scored than engraved. And I have 4 more blanks. But for Christmas, here’s hoping my 8 year old doesn’t mind.
The roughness is because you did a very hard engrave, your power lpi and speed combo dumped a lot of laser energy into the stone causing to to crack and spall.
If you ever give it another shot, I’d say you could ramp up the speed to 1000, power 100, 270lpi. It’ll go faster and the end result probably won’t be as rough (though it won’t be deep either).
Cutting depth in the stone with the laser isn’t a very successful process. The beam just can’t do it smoothly. A Dremel with a diamond bit could do it but it’s not exactly what you’re asking for, sounds like.
