SIDERITE, Marro Velho Minas Gerais BRAZIL (miniature)

Siderite is a mineral made up of iron(II) carbonate (FeCO3), deriving its name from the Ancient Greek term σίδηρος (sídēros), which translates to "iron." This mineral is an important iron ore, containing 48% iron and is free from sulfur and phosphorus. Iron can be substituted by elements such as zinc, magnesium, and manganese, leading to the formation of solid solution series like siderite-smithsonite, siderite-magnesite, and siderite-rhodochrosite.

With a Mohs hardness ranging from 3.75 to 4.25 and a specific gravity of 3.96, siderite exhibits a white streak and displays either a vitreous or pearly luster. It becomes antiferromagnetic at temperatures below its Néel point of −236 °C (4K), a characteristic that can aid in its identification.

Miniature