Niccolite is a nickel arsenic ore, is a mineral, classified by Dana's Manual of Mineralogy, and is a minor source of nickel (Ni). Niccolite is an arsenide of nickel mineral. Niccolite's color ranges from a gray to a copper color. Arsenic can be replaced by antimony. The specific gravity of this mineral ranges from 7.3 to 7.7, and it may contain small quantities of iron, cobalt or sulphur. Due to its color, it was referred to as "Copper Nickel", at one time. Nickel is ferro-magnetic, which, when used with iron and cobalt, manufactures a good strength magnet. Celestial visitors to the planet have a 5 to 20% mixture of Nickel-Iron, which distinguish them from earth rocks. Nickel is primarily used as an alloy to metals, with stainless steel being the major use of nickel. Other nickel alloys include super alloys, which are stronger and more corrosion resistant metals that are used in high temperature applications, where a particular strength is required.   Some information provided by USGS