These are unusual dichroic yellow and blue moissanite facet rough. Each is labelled with its gram weight and letter in the photo and they can be purchased individually.
This one is an odd one--moissanite with striking dichroism! This is the result of a mistake during growth where the argon atmosphere was lost and atmospheric nitrogen snuck and an was able to color the crystal partway through growth. This gives it a very unique look--when cut the colors may blend to green or remain separate depending on the chosen orientation and cut design. This is one of my favorite materials to cut and it comes out amazing!
Note that this is the newer '4H' polytype of moissanite. The crystal structure has been improved over the older versions, which means you don't have the same worries about a yellow discoloration during polishing.
