Sphalerite facts for kids

Quick facts for kids Sphalerite
General
Category	Sulfide mineral
Formula (repeating unit)	(Zn,Fe)S
Strunz classification	2.CB.05a
Dana classification	02.08.02.01
Crystal symmetry	F43m (No. 216)
Unit cell	a = 5.406 Å; Z = 4
Identification
Color	Brown, yellow, red, green, black.
Crystal habit	Euhedral crystals – occurs as well-formed crystals showing good external form. Granular – generally occurs as anhedral to subhedral crystals in matrix.
Crystal system	Cubic
Twinning	Simple contact twins or complex lamellar forms, twin axis [111]
Cleavage	perfect
Fracture	Uneven to conchoidal
Mohs scale hardness	3.5-4
Luster	Adamantine, resinous, greasy
Streak	brownish white, pale yellow
Diaphaneity	Transparent to translucent, opaque when iron-rich
Specific gravity	3.9–4.2
Optical properties	Isotropic
Refractive index	nα = 2.369
Other characteristics	non-radioactive, non-magnetic, fluorescent and triboluminescent.

Sphalerite is a common mineral that is a mix of zinc and iron sulfide. Its chemical formula is (Zn,Fe)S. This means it contains zinc, iron, and sulfur. Sphalerite can be many colors, like brown, yellow, red, green, or black. It often looks like galena, which is a lead ore. Miners sometimes called it "zinc blende" because it looked like galena but didn't contain lead.

Sphalerite is not very hard. On the Mohs hardness scale, it ranks between 3.5 and 4. It is the most important source of zinc in the world. It has a shiny, non-metallic look, sometimes like resin or grease.

Where is Sphalerite Found?

Sphalerite is found all over the world. The top countries that produce sphalerite include the United States, Russia, Mexico, Germany, Australia, Canada, China, Ireland, Peru, Kazakhstan, and England.

Some places are known for having very high-quality sphalerite crystals:

What is Sphalerite Used For?

A Source for Metals

Sphalerite is super important because it's the main source of zinc. About 95% of all the zinc we use comes from sphalerite ore. But it's not just for zinc! Sphalerite also contains small amounts of other valuable metals. These include cadmium, gallium, germanium, and indium. These metals can replace zinc in the mineral's structure.

Making Brass and Bronze

The zinc from sphalerite is used to make brass. Brass is a metal mix, or alloy, made mostly of copper and zinc. People have been using sphalerite to make brass for a very long time. For example, during the medieval ages (from the 7th to the 16th century CE), Islamic cultures used it. It was also likely used in Northern China in the 12th–13th centuries CE during the Jin Dynasty.

Sphalerite's zinc can also be used to make certain kinds of bronze. Bronze is another alloy, mainly copper mixed with other metals like tin, zinc, lead, or nickel.

Other Cool Uses

• Building Materials – Sphalerite can be found inside Yule Marble. This special marble was used to build famous landmarks like the Lincoln Memorial and the Tomb of the Unknown Soldier.
• Protecting Metal – Zinc from sphalerite is used in a process called galvanizing. This adds a protective coating to iron to stop it from rusting. You can find galvanized iron on power lines, nails, and cars.
• Batteries – Zinc is a key material in many types of batteries.
• Jewelry – Sometimes, high-quality sphalerite crystals are cut and polished to be used as gemstones.

Images for kids

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  The crystal structure of sphalerite

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  Sharp, tetrahedral sphalerite crystals from the Idarado Mine, Colorado, US.

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  A beautiful, cherry-red sphalerite crystal from Hunan Province, China.

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  A cut and polished sphalerite gemstone, weighing 3.86 carats, from Spain.

See also

In Spanish: Esfalerita para niños