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Back from the gemshow in bangkok we bought the rare stone Sultanite ("Diaspore") against very good prices and furthermore 50-80% DISCOUNT on everything in Hall 2, 3 & 4 Lava outdoor images up to 70% off, all horns, shells and ocean drums also 60-70% Discount. Come quickly, very interesting! Raw stones and Madagascar products from as little as 1.50 / kilo.

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Prehnite with Tourmaline tumbled stones from Mali

Prehnite with Tourmaline tumbled stones from Mali


Prehnite with Tourmaline tumbled stones from Mali


Well-tumbled stones with beautiful polished shine.




More information

The mineral Prehnite is a calcium-aluminum-silicate with the chemical formula Ca2Al2Si3O10 (OH). The mineral belongs to the fylosilicaten. The transparent to translucent, colorless, white, gray or yellow to yellow-green prehnite has a glass to pearl luster, a white stripe color and cleavage is clear according to the crystal surface [001]. Prehnite has an average density of 2.87, and the hardness is 6 to 6.5. The crystal system is orthorhombic and the mineral is not radioactive. The mineral prehnite is named after the Dutch colonel Hendrik von Prehn (1733 - 1785), who discovered the mineral in South Africa. Prehnite was the first mineral, which was named after a person. Prehnite is a mineral that occurs fairly common in hydrothermal weathered rocks. Although it is not a zeolite, it is often found in the vicinity of zeolites. It is among others found in granites, gneisses and syenieten. It is also indicative mineral for the low-grade metamorphic facies prehnite-pumpellyiet. The type of location is Haslach, Harzburg Oberstein, Germany.