Carlosturanite, new asbestiform rock-forming silicate from Val Varaita, Italy
Carlosturanite, new asbestiform rock-forming silicate from Val Varaita, Italy
American Mineralogist (August 1985) 70 (7-8): 767-772
- Alps
- cell dimensions
- chain silicates
- chrysotile
- clinohumite
- clinopyroxene
- crystal chemistry
- crystal structure
- diopside
- Europe
- fluorides
- forsterite
- geochemistry
- halides
- hematite
- humite group
- Italy
- magnetite
- metaigneous rocks
- metamorphic rocks
- metasomatic rocks
- mineralogy
- minerals
- nesosilicates
- new minerals
- olivine group
- orthosilicates
- oxides
- perovskite
- Piedmont Alps
- pyroxene group
- serpentine group
- serpentinite
- sheet silicates
- silicates
- Southern Europe
- TEM data
- Western Alps
- X-ray data
- Balangero
- Sampeyre
- Monviso
- carlosturanite
- unarovite garnet
- metaxite
- Val Varaita
Carlosturanite (M (sub 21) T (sub 12) O (sub 28) (OH) (sub 4) (OH) (sub 30) .H (sub 2) O, Cm, a 36.70, b 9.41, c 7.291 A, beta 101.1 degrees , Z = 2, D (sub (calc)) 2.606, D (sub (obs)) 2.63 g/cm (super 3) ) is a new rock-forming silicate occurring in a network of veins cross- cutting the antigorite serpentinite of Sampeyre in the Monviso ophiolite, Italy. The strongest XRD lines are: 7.17(100), 3.397(55), 3.595(45) , 2.562(40), 2.280(35), 18.02(25) A. The mineral is light brown, asbestiform, and the (010) fibres are paralleled by fibrous diopside and chrysotile. Similar refractive indices (1.605 and 1.600) are measured along and across the fibre axis. Carlosturanite or carlosturanite-like phases may be expected to develop in serpentinite compositions under low-grade metamorphic conditions.
