You could perhaps get the opinion that beryl is not that uncommon in Australia. Mindat lists 3 pages of NSW localities, 3 pages of them from WA, and around half a page each from NT, QLD, VIC, TAS and SA. Wherever you find granites you’ll tend to find pegmatites and hence tend to find beryl. But it’s still pretty scarce … I’ve never seen any in the field in my travels, but that’s just because I haven’t been to any of the sites listed! Beryl is a mineral composed of beryllium aluminium silicate, Be3Al2(SiO3)6 and is a commercial source of beryllium. Several varieties are valued as gemstones including aquamarine (pale blue-green), emerald (deep green), heliodor (golden yellow), goshenite (clear) and morganite (pink). Beryl is a minor constituent of many granitic rocks and associated pegmatite dikes, in gneisses, and in mica schists. The gem varieties (other than emerald) commonly are found in cavities in pegmatites. Emeralds can occur in mica schist, e.g. at Poona in WA. Some more details … Luster: Vitreous. Transparency: Crystals range from transparent to translucent. Crystal System: Hexagonal (classic stumpy six-sided prisms for the garden-variety non-gemmy beryl) Cleavage: imperfect in the basal plane. Hardness: 7.5 - 8. Streak: White Looking forward to seeing your examples …
Posted on: Fri, 12 Sep 2014 19:17:46 +0000
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