HELLYERITE WITH HAEZLEWOODITE, LORD BRASSEY MINE , TASMANIA (miniature)

Hellyerite, with the chemical formula NiCO3·6(H2O), is a hydrated mineral composed of nickel carbonate. It typically exhibits a color range from light blue to bright green and has a hardness rating of 2.5. This mineral features a vitreous luster, leaves a white streak, and crystallizes in the monoclinic system. Its crystal structure is characterized by platy and mammillary encrustations on its matrix. According to X-ray crystallography, Hellyerite is classified as a pentahydrate, consisting of [Ni2(CO3)2(H2O)8] subunits, along with an additional pair of water molecules for hydration.

The mineral was first discovered in 1958 at the Old Lord Brassy mine in Tasmania, Australia, where this old specimen originates from (approx 1962).  It was named in honor of Henry Hellyer, who served as the Chief Surveyor for the Van Diemen's Land Company from 1791 to 1832.

Heazlewoodite, with the chemical formula Ni3S2, is a rare nickel sulfide mineral that is low in sulfur and typically found in serpentinitized dunite. This mineral appears as clusters and masses of opaque grains that range in color from metallic light bronze to brassy yellow, and it crystallizes in the trigonal system. Heazlewoodite has a hardness rating of 4 and a specific gravity of 5.82. It was first identified in 1896 in Heazlewood, Tasmania, Australia.

The Lord Brassey Mine is the type locality for both minerals.