Sanbornite is a rare barium phyllosilicate mineral with formula BaSi<sub>2</sub>O<sub>5</sub>. Sanbornite is a colorless to white to pale green, platey orthorhombic mineral with Mohs hardness of 5 and a specific gravity of 3.74.
It was first described from Incline, Mariposa County, California in 1932 and named for mineralogist Frank B. Sanborn (1862âÂÂ1936).