Here are the important things to know when engraving on stones with a laser.
-Only engrave stones that are dry.
-Measure your stone. Is it small enough to fit in the laser without removing the tray? If not, remove the tray and build up a platform for the stone to sit on until it is at the correct level for engraving.
-What kind of stone are you engraving? If you are engraving colored glass stone it helps the engrave to come out better if you cover the stone with a thin layer of liquid dish soap and engrave while the dish soap is still wet.
-Secure you stone to the laser bed. You can do this with play dough, honeycomb pins, tape, modeling clay, scrap material, etc. Just make sure it isn’t going to move when the laser starts! Try and level the stone out flat as much as possible so that you get an even engrave.
-Outlines engrave better than lots of small details on most stones, especially glass.
-After engraving wash/clean the stone.
-If it is hard to see the engraving you can fill the engrave with paint so that it stands out more. You can engrave the stones masked if you want to paint and not have cleanup after.
Here is a list of Glowforge laser settings to try with different stones:
Agate: 500/full 270LPI focus on stone or manual focus
Agate scored: 125/21 focus on the stone or manual focus
Hard River Rock: 125/full 270 LPI or more, focus on stone or manual focus
Marble looking smooth stone: 500/full 270 LPI focus on stone or manual focus
Colored Glass stone: thin layer of dish soap. 500/full 270 LPI focus on stone or manual focus.
Plain Glass stone: thin layer of dish soap engrave when still wet.
950/100 225 LPI focus on stone or manual focus
Gold stone: 500/full 270 LPI focus on stone or manual focus
Green stone : 500/full 270 LPI focus on stone or manual focus
Faux Turquoise stone: 1000/full 270 LPI. Focus on stone or manual focus