A green mineral of the amphibole group containing calcium, magnesium, and iron and occurring chiefly in metamorphic rocks and as a form of asbestos.
'Amosite, fibrous anthophyllite, fibrous tremolite, fibrous actinolite, and crocidolite are amphiboles, double-chain silicates, which observed microscopically look like sharp needles.'
'They have a mineralogical association of quartz, diopside, actinolite, plagioclase and K-feldspar.'
((n.) A bright green variety of amphibole occurring usually
in fibrous or columnar masses.)
Origin:
Late 18th century: from Greek aktis, aktin- ‘ray’ + lithos ‘stone’ (because of the ray-like crystals).
