1) Monoclinic mineral 
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 and is red-orange, pinkish brown to dark brown in color and colorless in thin sections. The mineral h...