I googled Volcanic glass and did not see anything close. Then I ran across Sunstone, but there isn't the color spectrum inside. There are swirls inside and also bubbles. There is rough texture semi abrasive.It scratches glass maybe a moh 7 or 8. I didn't do any other tests, not knowing how it would affect the piece. It does have a lapidary cut on the bottom. I was thinking just glass slag but the detail is too intricate according to my research. The bubbles are what is making me question fake.
1lb 16oz 5" H from widest part 4"w