Some associated minerals include&colon; calcite, galena, pyromorphite, smithsonite, vanadinite, and wulfenite. Vanadinite () and other vanadium bearing minerals are only mined in exceptional cases. Crystals of vanadinite conform to a hexagonal system of symmetry. Over 60 vanadium ores are known, including vanadinite, patronite, and carnotite. Other names that have since been given to vanadinite are johnstonite and lead vanadate. Vanadinite deposits are found in over 400 mines across the world. Vanadinite is particularly heavy for a translucent mineral. Del Rio's lead mineral was later renamed vanadinite for its vanadium content. Some noteworthy minerals from the Castle Dome Mountains region are vanadinite, wulfenite, baryte, and fluorite. Vanadinite is also occasionally used as a source of lead. Vanadinite is a lead chlorovanadate with the chemical formula Pb(VO)Cl. Vanadinite is especially found in association with the lead sulfide, galena. Vanadinite is very brittle, producing small, conchoidal fragments when fractured. Vanadinite when containing a high amount of the arsenic impurity is known as endlichite. Vanadinite is anisotropic, meaning that some of its properties differ when measured along different axes.