Tiger’s eye, both tumbled and rough. Tiger’s eye is a variety of quartz, and is also a pseudomorph. Tiger’s eye begins its life as crocidolite, a type of asbestos—this is where it gets its very thin fiber appearance from. The asbestos is replaced by silica, resulting in this chatoyant rock. In fact, the specimen on the bottom appears to be only a partial pseudomorph—the blue parts are likely still crocidolite.