This unusual deposit of Black Tourmaline, also known as Warrierite, is located on an island in the middle of a normally dry salt lake. The name Warrierite is due to its location on Warriedar Station, once a large sheep grazing property approximately 450 km north of Perth, Western Australia.

The Black Tourmaline from this deposit is a very fine grain, massive variety, it does not form as crystals, with pieces of 50 kg or more not uncommon. The tourmaline mineralization, which is found only on the island, has been subjected to trace-element analysis and other testing, and found to be a microcrystalline form of dravite–schorl.

The age of the Black Tourmaline itself has not been conclusively dated, but the Tourmaline Island deposit is thought to be part of the Warriedar Fold Belt, an Achaean geological formation around 3 billion years old.

With a MOH’s hardness of 7 – 7.5, this material takes a very high polish. Black Tourmaline is often cut into cabochons, beads and other jewellery, carvings and other ornamental uses. It is a powerful metaphysical stone, and is said to both repel and protect against negativity.