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Tourmaline VIII - Cyclosilicates

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Name		Tourmaline
Chemistry		Na(Mg,Fe3Al6[(OH)4|(BO3)3|Si6O18]
Hardness		7
Lustre		vitreous
Colour		colourless and in all colours
Streak		white
Density [g/cm3]		3.0 - 3.3
Crystal habit		trigonal, crystals columnar with ditrigonal cross section, striated
Cleavage, Fracture		fracture conchoidal to uneven
other characteristics and occurrences		schorl     = black variety achroite   = colourless indicolite = blue rubellite  = red, pink verdelite  = green in pegmatites, inclusions in quartz (tourmalinated quartz)

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© 2004 Büro für angewandte Mineralogie · Dr. Stephan Rudolph · D-47918 Tönisvorst

These recommendations are believed to be correct. However, no guarantee of their accuracy is given. Therefore, purchasers shall make their own tests to determine suitability for their use. These products are offered for industrial and related uses (e.g. research and development) only. However the user must take the necessary precautions appropriate for products containing chemicals. This description does not imply the absence of any patents, the responsibility whatsoever solely rests with the user.