crocidolite

n. [ Gr. kroky`s nap on cloth + -lite. ] (Min.) A mineral occuring in silky fibers of a lavender blue color. It is related to hornblende and is essentially a silicate of iron and soda; -- called also blue asbestus. A silicified form, in which the fibers penetrating quartz are changed to oxide of iron, is the yellow brown tiger-eye of the jewelers. [ 1913 Webster ]