3.8" Lustrous Siderite Crystal Cluster on Quartz - Peru

These are lustrous brown rhombohedral siderite crystals that formed from a quartz crystal encruste, pyrite-rich matrix, collected from the Julcani Mine in Huancavelica, Peru. There also appear to be small yellow sphalerite crystals peppered throughout the specimen.

Comes with an acrylic display stand.

Siderite, also known as "chalybite", is an iron carbonate mineral that belongs to the calcite group. It can contain a wide variety of impurities including manganese, magnesium, calcium, zinc and cobalt. Hues of brown are typical for siderite, with the occasional white and gray specimens. It can occur as rhombohedral crystals with rounded faces and in rare cases, it's found as scalenohedral crystals. Botryoidal, concretionary, massive, stalactitic and mammillary are some of the more common formations of siderite.

Being that siderite is such a prevalent mineral, it can be found all around the world in a wide variety of colors and formations. A noteworthy location that produces beautiful gemmy siderite specimens is the Morro Velho Mine in Minas Gerais, Brazil. The crystals collected from here are often translucent, yellow-green in color and form in association with dolomite, cubanite, pyrrhotite and chalcopyrite.

The chemical formula of siderite is FeCO3 with the variable formula including manganese, magnesium, calcite, zinc and cobalt ((Fe,Mg,Ca,Mn,Zn,Co)CO3).

Silicon Dioxide, also known as SiO2 or Quartz, is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich, hot watery solutions called hydrothermal environments, at temperatures between 100°C and 450°C, and usually under very high pressure. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountains forming, and can be hundreds of millions of years old.
Siderite, Quartz & Pyrite
Julcani Mine, Julcani District, Angaraes Province, Huancavelica, Peru
3.8" wide