Mineral description : Høgtuvaite

Picture pending, from Høgtuva.

Mineral class	Silicates : Cyclo silicates : Beryl tourmaline group
Chemical formula	(Ca,Na)2(Fe2+,Fe3+,Ti,Mg,Mn)6(Si,Be,Al)6O20
Crystal system	Triclinic, class : /1, Space group P/1, Z=2
Lattice constants	a=10.317 b=10.724 c=8.855 alpha=105.77 beta=96.21 gamma=124.77
Diffraction lines	2.5293(100) 8.048 (90) 2.0979(63)
Optical constants	alpha=1.78 beta, gamma=1.82 (-)2V=...
Habitus	As thin flat striated tabular crystals
Cleavage	None, fracture uneven.
Hardness	5.5
Density	3.85 (calc 3.98)
Color	Black
Streak	Greenish black.
Luster	Subadamantine, subtranslucent to opaque.
Description	A rare mineral only used as mineral specimens.
Occurance
Associates	Zircon
Notes	Author: Grauch et al. 1994 Ref : Canadian Mineralogist. 1994, Jun, v32, ISSN 0008-4476, pg 439 Ref : Min.Mag.,37th List of New Min.,p523,1996 Not IMA approved mineral name : Makarochkinite Strunz Nr: 8/F.14-35
Locations	A very rare mineral with only two known localities Høgtuva, near Mo i Rana, Nordland, Norway. As flat crystals up to 3 cm in a quartz and zircone rich rock (is it a schist ???).

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