Sanbornite is a rare barium phyllosilicate mineral with formula: BaSi2O5. 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 (1862-1936).