Sphalerite

Sphalerite is the most important ore of zinc. Around 95% of all primary zinc is extracted from sphalerite ore. However, due to its variable trace element content, sphalerite is also an important source of several other elements such as cadmium, gallium germanium, and indium.

Sphalerite's color is usually yellow, brown, or gray to gray-black, and it may be shiny or dull. Its luster is adamantine, resinous to submetallic for high iron varieties. It has a yellow or light brown streak, a Mohs hardness of 3.5–4, and a specific gravity of 3.9–4.1. Some specimens have a red iridescence within the gray-black crystals; these are called "ruby sphalerite". The pale yellow and red varieties have very little iron and are translucent. The darker, more opaque varieties contain more iron. Some specimens are also fluorescent in ultraviolet light.

A striped rock

Bands of sphalerite

The refractive index of sphalerite (as measured via sodium light, average wavelength 589.3 nm) is 2.37. Sphalerite crystallizes in the isometric crystal system and possesses perfect dodecahedral cleavage.

Gemmy, pale specimens from Franklin, New Jersey (see Franklin Furnace), are highly fluorescent orange and/or blue under longwave ultraviolet light and are known as cleiophane, an almost pure ZnS variety.

Sphalerite is the major ore of zinc and is found in thousands of locations worldwide. Sources of high quality crystals include:

Sphalerite is a widely distributed ore that is the principal source of zinc, an element with many industrial uses, including non-corrosive alloys and protective coatings. Sphalerite is mined by underground or open mining and zinc is separated from the other constituent minerals by grinding the or using selective flotation to separate zinc.

The mineral crystallizes in the cubic crystal system. Like other minerals with a cubic crystal structure, sphalerite may show a tetrahedral crystal habit. In the crystal structure, zinc and sulfur atoms are tetrahedrally coordinated. The structure is closely related to the structure of diamond. The hexagonal analog is known as the wurtzite structure. The lattice constant for zinc sulfide in the zinc blende crystal structure is 0.541 nm. All natural sphalerites contain concentrations of various impurity elements. These generally substitute for the zinc position in the lattice. The most common are Cd and Mn, but Gallium, Germanium and Indium may also be present in relatively high concentrations (hundreds to thousands of ppm). The abundances of these elements are controlled by the conditions under which the sphalerite formed, most importantly formation temperature and fluid composition.

Sphalerite is considered a grounding stone and may be beneficial to overcome or prevent nervous exhaustion and fatigue. It works on the lower chakras to improve stamina and increase energy. For those working with powerful crystals, this stone is perfect for restoring calm and balance. It can help discern between a person's imagination and reality when they are channeling the higher realm.