We have seen that on certain types of stone, the GF permanently discolors the design on the surface, and that on marble it actually etches (removes material) as it works. My question is whether or not any of the beta users or pre-releasers have found if there is other types of stone where it removes material as it etches?
Here’s a rock @dan picked up outside the Glowforge office and then etched:
One of the things I am most excited about
Doesn’t this GF engraved rock look a little like the Fresnel lens created penguin by @gernreich?
Curiouser and curiouser. - Rich
I agree it does look the same. If you look closely at each they are a shiny black substance.