Kanoite

Kanoite is a light pinkish brown silicate mineral that is found in metamorphic rocks. It is an inosilicate and has a chemical formula of (Mg,Mn2+)2Si2O6.[1] It is a member of pyroxene group and clinopyroxene subgroup.[4]

Kanoite
Kanoite displayed at Mining Museum of Akita University.jpg
Kanoite exhibited at the Mining Museum of Akita University, Japan
General
CategorySilicate mineral (pyroxeneinosilicate)
Formula
(repeating unit)
(Mg,Mn2+)2Si2O6
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/c
Unit cella = 9.73, b = 8.93
c = 5.26 [Å]; β = 108.56°; Z = 4
Identification
Formula mass246.73 g/mol
ColorLight pinkish brown
TwinningPolysynthetic
CleavagePerfect on {110}, {110} - {110} = 88°
Mohs scale hardness6
Lustervitreous
DiaphaneitySemitransparent
Specific gravity3.66
Optical propertiesBiaxial (+)
Refractive indexnα = 1.715 nβ = 1.715 nγ = 1.728
Birefringence0.0130
2V angle40-42 measured
References[1][2][3]

CrystallographyEdit

Kanoite crystallizes in the monoclinic crystal system. Its Hermann–Mauguin Symbol is 2/m. Under this crystal system, the three axes of the crystal are all different in length. The a and the b axes are perpendicular, and b and c axes are perpendicular. The a and c axes make an oblique shape. The axial ratio for kanoite is a:b:c =1.0894:1:0.5884 and the cell dimensions are: a = 9.73, b = 8.93 and c = 5.26 Å with Z = 4.[2] Kanoite has a 2-fold axis and a mirror plane.

Kanoite is birefringent. It occurs as a mineral has 3 different indices of refraction. When the light passes through the Kanoite medium, the light splits due to unequal reflection from the crystal faces. As kanoite is birefringent, it is also anisotropic. In an anisotropic mineral, the velocity of light differs as the direction of the crystal changes.

Discovery and occurrenceEdit

Kanoite is a rare mineral which was found in Tatehira mine, KumaishiOshima PeninsulaHokkaidoJapan in 1977. In the type locality kanoite occurs along a joint that cuts a pyroxmangite-cummingtonite metamorphic rock in a manganese ore deposit. The region has undergone contact metamorphism as magma intruded the area. It was named to honor Hiroshi Kano, a petrology professor at Akita University in Japan.[1]

It has also been reported from Broken HillNew South WalesAustralia, the Semail Ophiolite in Oman, and the Balmat–Edwards zinc district, Saint Lawrence County, New York.[2]

This article uses material from the Wikipedia article
 Metasyntactic variable, which is released under the 
Creative Commons
Attribution-ShareAlike 3.0 Unported License

Note

This article uses material from the Wikipedia article
 Metasyntactic variable, which is released under the 
Creative Commons
Attribution-ShareAlike 3.0 Unported License
.