Brianite is a phosphate mineral with the chemical formula Na2CaMg(PO4)2. It was first identified in an iron meteorite. This mineral is named after Brian Harold Mason (1917–2009), a pioneer in meteoritics. It was first reported from the Dayton meteorite in Montgomery County, Ohio in 1966. It occurs in phosphate nodules within the meteorite. Associated minerals include: panethite, whitlockite, albite, enstatite, schreibersite, kamacite, taenite, graphite, sphalerite and troilite.