Noun
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.
Source: Webster's dictionaryThe first two are blue fibrous minerals, with glaucophane occurring in blueschists and crocidolite (blue asbestos) in ironstone formations, both resulting from dynamo-metamorphic processes. Source: Internet
The Cummingtonite/grunerite series is often termed amosite,or Brown Asbestos and riebeckite is known as crocidolite or Blue Asbestos. Source: Internet