Crinoid Marble is the marble remnant from a sea floor that contains fossil crinoids and other fossils. This gemstone fossil cabochon material came from China.
Crinoids were plantlike creatures shaped like lilies with long stems. Though they looked like plants, they were actually sea creatures, and are relatives to the sea urchin and starfish. There are actually 100's of different crinoid species, and they are believed to have lived on the earth as long as 490 million years ago. They were plentiful in the Paleozoic Period, but are now pretty much extinct. They are members of the echinoderms family. They mostly lived in deep water, but could be found in shallow water too.
The name Crinoid comes from the Greek word krinon, meaning lily. These fossil cabochons are believed to be about 354 million to 323 million years old.
I have these interesting fossil cabochons available in 2 sizes. The larger ovals are 52 mm (2 inches) by 38 mm . The smaller are only 30 mm by 22 mm. The backs are not polished and the bottom edges may have some chattering.