Breithauptite is a rare mineral composed of nickel arsenide with the chemical formula NiAs. It belongs to the arsenide mineral group and crystallizes in the hexagonal crystal system. This mineral is named after the German mineralogist Johann Friedrich August Breithaupt, who made significant contributions to mineralogy. Breithauptite is most commonly recognized by its distinctive copper-red to pinkish metallic color, which may tarnish over time to darker shades such as brown or gray due to oxidation. It has a metallic luster and is typically opaque, meaning it does not allow light to pass through. Because of its metallic nature, Breithauptite lacks the transparency and brilliance seen in traditional gemstones.