This is 'zombie' garnet, a type of lab-created YAG laser garnet whose composition I do not precisely know. Smaller pieces can be purchased by weight range and larger pieces are labelled with their gram weight and letter in the photo and they can be purchased individually.
This is an weird one, YAG doped with cerium and...something else? This material was sold to us as chromium YAG sight unseen, but when we got it in it was clear it was not normal chromium YAG. The variable yellow color and fluorescence all but guarantee it contains cerium, but the unusual green hue is very odd. It may be a combination of cerium and chromium, or maybe a valence thing, or uh. I don't know. The result is a very strange look, a swampy yellow-green with an odd glow that makes it look almost opaque in some lighting.
YAG has an RI of 1.83, hardness of 8.5 and cuts and polishes very easily. It is ideal for all jewelry applications. This is a great stone for beginners who want an uncomplicated cut or advanced cutters who want to show off their skills.
