It was first described from the Melones and Stanislaus mine in Calaveras County, California in 1866.
Melonite occurs as trigonal crystals, which cleave in a (0001) direction. It has a specific gravity of 7.72 and a hardness of 1-1.5 (very soft).
In the metal finishing industry, Melonite is a trademark referring to a molten salt bath nitrocarburizing process, similar to Tenifer. This process can be applied to steels to increase corrosion and abrasion resistance, and improve other surface properties.