Exotica Jasper is also been called Sci Fi Jasper and Porcelan Jasper. Jasper is an opaque, microcrystalline form of quartz. As with any microcrystalline quartz, it is hard and works well. It takes a good polish with diamond, aluminum oxide or tin oxide.
Ruler is in INCHES.
Example of a Exotica Jasper Cabochon.
Note: Not cut from material below.