Black onyx pendant
Onyx is a tightly banded agate - a stripy stone. For some reason, people think of onyx as a black stone. It's not, generally. However, this stone is called black onyx, and who am I to argue? It's black, at least. Just... not stripy.
It's silver set, from Brazil and with a nice faceted cut.
Oval shape - 30mmx25mm.