Mn₉(SiO₄)₄ (OH,F)₂

This sample of sonolite is displayed in the Smithsonian Museum of Natural History. It is described as zincite with franklinite and sonolite. The sonolite is the red-orange material. Sonolite is a silicate mineral of manganese which contains fluorine. It has the composition Mn₉(SiO₄)₄(OH,F)₂. This sample is about 11x11 cm and is from Franklin, New Jersey.