Sphalerite with siderite refers to mineral specimens where both sphalerite (zinc sulfide, ZnS) and siderite (iron carbonate, FeCO₃) are found together in the same geological context. Sphalerite with siderite commonly occurs in hydrothermal mineral deposits. These deposits form under conditions of elevated temperature and pressure, often in association with fluids rich in metals.
Sphalerite crystallizes in the cubic crystal system and commonly forms tetrahedral crystals. It can also occur in massive, granular, or botryoidal forms. Sphalerite exhibits a wide range of colors including yellow, brown, red, and black. The color variation is often due to its iron content, which also affects its gemological names such as ruby jack (red) and marmatite (black).
Siderite crystallizes in the trigonal crystal system and commonly forms rhombohedral or scalenohedral crystals. It can also occur in massive forms. Siderite ranges in color from yellowish-brown to brown and occasionally gray or white. It has a vitreous to pearly luster.
Peru is home to significant deposits of sphalerite as well as siderite is also found in various regions of the country.
MEASUREMENT DETAILS:
3"L x 2.50"W x 1 1/8"H
