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Russian Gemstones Encyclopedia

Vladimir Bukanov. Russian Gemstones Encyclopedia

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ASTROPHYLLITE


ASTROPHYLLITE (Astrophyllit—Astrophyllite—јстрофиллит) (Scheerer, T. 1854), from Gk. ”astron” – brilliant (star) and “phyllon” – a leaf, alluding to its high luster and foliate habit. He has a synonym asterophyllite. Silicate – (K,Na)3(Fe2+,Mn)7Ti2[(O,OH)7|(Si4O12)2], according the specific of its structure it takes an intermediate position between the subclasses of chain and sheet silicates. Triclinic system. Hardness 2-3. Density 3.3-3.4. Glass luster to silk one in aggregates. Perfect cleavage in one direction. Fragile. Non-transparent to translucent in fine plates. Color: golden-brownish to golden-yellow. Astrophyllite is a rare mineral, which is found in the shape of flattened or needle crystals to 15 cm. or more, also in radial-rayed and twisted-fibrous aggregates, including in the form of astrophyllite suns. Atypical mineral pegmatites of nepheline syenites, also in alkaline granites.

Deposits. In Russia, on the Kola Penin., in Khibiny, they researched a deposits of astrophyllite in the Eveslogchorr Mt., Yukspor Mt. and Hackmann Canyon locality, with the calculated resources of collection rough material. There, they find also ornamental varieties of aegirine-astrophyllite albitite with astrophyllite suns and aegirine suns, as well as astrophyllite hair stone in albitite. They discovered more than ten ornamental texture varieties of astrophyllite there, with the trade names: “Star of Lapland”, “Sun”, “Golden Rain” and others. In the Lovozero, alkali massif there are as well astrophyllite rocks. Besides, in the Western Keivy Ridge, near Rovozero Lake, astrophyllite was discovered in the quartz nucleus of a pegmatite vein, where its inclusions in quartz form hair stone from fine plates up to 50 cm. long. In the Khabarovsk Region, in the Dzhugdzhur Ridge, rocks with astrophyllite were discovered in the Ulkanskiy complex, in the upper reaches of the Uchur River. In the East Kazakhstan, in the Tarbagatai Ridge, rocks with astrophyllite are known in the Akzhailyau massif; and in Southern Kyrgyzstan – in the Alayskiy Ridge, in the massifs Dzhilusu and Khoja Achkan. In Norway, there is a group of deposits with astrophyllite – Barkevik and Eikaholmen, in the Langesund region; Telemark, also at the Yttre Kjæs, and others. In South Greenland – in the Narssârssuk massif and in East Greenland – in Kangerdluarsuk fjord. In the U.S.A., in Colorado, rocks with astrophyllite are known at the Pekes Peak massif, El Paso Co; and also in the Massachusetts State. In New Hampshire, at the Newport deposit, astrophyllite was found in pegmatites. Besides, in states New Hampshire and Washington, Washington Pass locality, Okangon Co., astrophyllite is found in crystals of smoky quartz in the shape of sheaf-like inclusions up to 1 cm. long. In other countries, rocks containing astrophyllite are found in Egypt – in the Garib Mt.; in Nigeria – on Jos Plateau; in Spain – in the Pontevedra area, Galicia region; in South Africa – in the Pilanesberg massif; North-West Prov.; in Canada – in the Red Wine massif on Central Labrador, and at the Mont St Hilaire massif, Québec; in Guinea – on the Los Iss. Rocks with astrophyllite are processed in large cabochons, brooches and balls or used in souvenir produce.

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