This blog is a electronic museum of my collections of antiquities, ethnographic, first editions, retro pottery from the 1950's to early 1970's, shell, mineral and gemstone samples,fossils and other wonderful things! Comments are welcome on the objects including advice which will add to my own wonderment and knowledge.

Thursday, July 17, 2014

Mineral Specimen: Black Aegirine Acmite Crystal on Orthoclase

Chemical Formula: NaFeSi2O6
Provenance: Mt. Malosa, Zomba Valley District, Malawi, AFRICA
Size and Weight: 13 grams. Approx 4 x 3 x 0.8 cm

Usually found as a long, thin, prismatic or bladed crystal/s, with a pointed pyramid on top (clinopinacoidal), and very often embedded in a matrix. Fibrous masses, radiating sprays, and interlocking thin prismatic crystals are also common. May also be in reticulated masses and in grainy aggregates embedded in a matrix. Crystals are often striated lengthwise, and doubly terminated crystals are occasionally found. 

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