Sphalerite is a zinc sulfide mineral and the primary ore of zinc, known for its striking range of colors, including yellow, brown, red, green, and black, depending on its iron content. It has a high dispersion, giving well-cut gems a brilliant fire, though its relative softness (Mohs hardness of 3.5 to 4) makes it less suitable for everyday jewelry. Sphalerite is primarily found in hydrothermal veins and sedimentary deposits, with major sources including Spain, Mexico, the United States, Canada, and Bulgaria. Its distinct resinous to adamantine luster and high refractive index make it a desirable collector’s gemstone.