Millerite

It's advisable to handle millerite carefully to avoid generating dust and wash hands thoroughly afterward. When cutting or polishing millerite, wear a dust mask to prevent inhaling heavy metal particles. Store millerite in a sealed container in a well-ventilated area, away from children and pets. For those involved in crystal healing, never put it in your mouth.

Millerite is found as a metamorphic replacement of pentlandite within the Silver Swan nickel deposit, Western Australia, and throughout the many ultramafic serpentinite bodies of the Yilgarn Craton, Western Australia, generally as a replacement of metamorphosed pentlandite. There is one known occurrence of millerite in South Africa, near Pafuri in the Transvaal. The deposit has never been commercially mined. It is commonly found as radiating clusters of acicular needle-like crystals in cavities in sulfide rich limestone and dolomite or in geodes. It is also found in nickel-iron meteorites, such as CK carbonaceous chondrites. Millerite was discovered by Wilhelm Haidinger in 1845 in the coal mines of Wales. It was named for British mineralogist William Hallowes Miller. The mineral is quite rare in specimen form, and the most common source of the mineral is in the Halls Gap area of Lincoln County, Kentucky in the United States.

Millerite is a minor source of nickel, which is an important metal to many industries. Millerite is sometimes used for jewelry but is too soft for much practical use. Due to its rarity and beauty, it is often sought out by collectors.