Dark Multicolored Stone Cabochon in Vintage Bronze

I received this stone from my husband who, unfortunately, didn't remember what type of stone it was.  I have searched, but was unable to make a 100% positive ID, so I hesitate to call it anything.  It is a beautiful stone, however, with rust colored striations and an almost blue/green tint to the the rest.  If anyone recognizes the type of stone, please contact me so that I can finally give this lonely pendant a proper name.

The pendant is made with enameled copper core wire, which means you won't have to worry about tarnishing as time passes.  Please remember that jewelry should not be stored in direct sunlight and should be kept out of water if at all possible. 

Due to the nature of monitors and screens, the color may vary slightly in real life.

Weight: 0.8 ounces

Size (LxWxD): 2 3/4 x 1 1/4 x 1/2 inches

Weight: 24 grams

Size (LxWxD): 7 x 3.2 x 1.3 centimeters