Sonolite | |
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![]() Sonolite (in bottom left corner) with zincite and manganosite | |
General | |
Category | Silicate minerals |
Formula | Mn9(SiO4)4(OH,F)2 |
IMA symbol | Snl [1] |
Strunz classification | 9.AF.55 |
Dana classification | 52.3.2d.3 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | P21/b [2] |
Unit cell | a = 4.87 Å, b = 10.66 Å c = 14.28 Å β = 100.3°, Z = 2 [2] |
Identification | |
Color | Red-orange, pinkish brown to dark brown Colorless in thin section [2] |
Twinning | Common, singular or lamellar on {101} [2] |
Mohs scale hardness | 5.5 |
Luster | Vitreous, dull |
Diaphaneity | Transparent to translucent [3] |
Density | 3.82–4.00 (measured) [2] |
Optical properties | Biaxial (−) |
Refractive index | nα = 1.765 nβ = 1.778 nγ = 1.787 |
Birefringence | δ = 0.022 |
2V angle | 75° to 82° (measured) |
Dispersion | r > v [2] |
References | [4] |
Sonolite is a mineral with formula Mn9(SiO4)4(OH,F)2. The mineral was discovered in 1960 in the Sono mine in Kyoto Prefecture, Japan. In 1963, it was identified as a new mineral and named after the Sono mine.
Sonolite is transparent to translucent [3] and is red-orange, pinkish brown to dark brown in color and colorless in thin sections. The mineral has a granular habit or occurs as prismatic to anhedral crystals up to 2.5 cm (0.98 in). [2] Sonolite is the manganese analogue of clinohumite, [5] a dimorph of jerrygibbsite, [2] and a member of the humite group. [4]
The mineral occurs in metamorphosed manganese-rich deposits. Sonolite has been found in association with calcite, chlorite, franklinite, galaxite, manganosite, pyrochroite, rhodochrosite, tephroite, willemite, and zincite. [2]
In 1960, Mayumi Yoshinaga was investigating alleghanyite and other manganese orthosilicates in Japan. He discovered a dull, red-brown mineral on the first level ore body of the Sono Mine, and later from a number of other sites. [5] Using samples from ten locations in Japan and one in Taiwan, the mineral was described in 1963 and identified as a new mineral species. [6] It was named sonolite after the mine in which it was first found and the name was approved by the International Mineralogical Association. [4] [5]
As of 2012 [update] , sonolite has been found in Austria, France, Japan, Kyrgyzstan, Romania, Russia, Sweden, Switzerland, Taiwan, and the United States. [4] The type material is held at Harvard University in Cambridge, Massachusetts, US. [2]
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