Accessory phases include titanite, apatite, corundum, zircon, magnetite and ilmenite. Zircon, apatite, titanite, magnetite, ilmenite, and sulfides occur as accessory minerals. Typical skarn minerals include pyroxene, garnet, idocrase, wollastonite, actinolite, magnetite or hematite, epidote and scapolite. The basalt dunes are believed to contain the minerals chromite, magnetite, and ilmenite. Examples include galena, pyrite and magnetite. Hematite forms through chemical oxidation reactions of other minerals in the rock including magnetite. Bog ore often combines goethite, magnetite, and vugs or stained quartz. Oxides, such as magnetite or ilmenite, are also common. This includes iron ore, magnetite, hematite, and often pyrrhotite. Minerals that often display parting include the pyroxenes, hematite, magnetite, and corundum. Titanomagnetite may undergo oxyexsolution during cooling, resulting in ingrowths of magnetite and ilmenite. It occurs in a wide range of minerals including arsenopyrite, pyrite and magnetite. Pyrrhotite is often accompanied by pyrite, marcasite and magnetite. Besides gold, these minerals included silver, manganese, copper, magnetite, iron and nickel. It is commonly associated with olivine, magnetite, serpentine, and corundum.