| Sonolite | |
| Category: | Silicate minerals |
| Formula: | Mn9(SiO4)4(OH,F)2 |
| Imasymbol: | Snl[1] |
| Strunz: | 9.AF.55 |
| Dana: | 52.3.2d.3 |
| Class: | Prismatic (2/m) (same H-M symbol) |
| Symmetry: | P21/b |
| Unit Cell: | a = 4.87 Å, b = 10.66 Å c = 14.28 Å β = 100.3°, Z = 2 |
| Color: | Red-orange, pinkish brown to dark brown Colorless in thin section[2] |
| Twinning: | Common, singular or lamellar on |
| Mohs: | 5.5 |
| Luster: | Vitreous, dull |
| Refractive: | nα = 1.765 nβ = 1.778 nγ = 1.787 |
| Opticalprop: | Biaxial (−) |
| Birefringence: | δ = 0.022 |
| 2V: | 75° to 82° (measured) |
| Dispersion: | r > v |
| Density: | 3.82–4.00 (measured) |
| Diaphaneity: | Transparent to translucent[3] |
| 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 2.5cm (01inches).[2] Sonolite is the manganese analogue of clinohumite, 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. Using samples from ten locations in Japan and one in Taiwan, the mineral was described in 1963 and identified as a new mineral species. It was named sonolite after the mine in which it was first found and the name was approved by the International Mineralogical Association.[4]
, 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]