Handmade in the USA by Ingrid Shourds-Dalton. 
I make a lot of jewelry from recycled materials. I have no idea where I got this interesting pendant or what it is made from, to be honest. It looks like black agate. It could be faux black agate. It is black with white in it, with tiny rhinestones around the stone. I had this round, black and white glass bead for years. I only had one like it and finally decided they would go well together with the pendant and some silver tone hardware and beads with more little faux diamonds. Then, I put it on a silver tone snake chain.
This necklace is about 12 inches from clasp to bottom of pendant. The entire pendant is about 2.56 inches. Just the chain is about 9.646 in. 
I can always lengthen or shorten a chain for no extra charge if asked. 
Make sure to look at all pictures to see it in different lighting. See the rhinestones sparkle!