Apatite

General Information and Occurrences of Apatite

• Apatite is a phosphate mineral in the apatite group, with a hexagonal crystal system.
• It is usually green but can also be colorless, yellow, blue, violet, or pink.
• Apatite is commonly found as an accessory mineral in igneous and metamorphic rocks.
• It can also be found in clastic sedimentary rocks and phosphorite, a phosphate-rich sedimentary rock.

Uses of Apatite

• Apatite is primarily used as a source of phosphate in fertilizer manufacturing and other industrial applications.
• It has been used as a pigment in ancient Chinese terracotta and enamel for metalware.
• A byproduct of apatite digestion with sulfuric acid is hydrogen fluoride, which can be used in the production of hydrofluoric acid.
• Apatite can be a source of uranium and vanadium as trace elements.
• It was used in the Halophosphor fluorescent tube phosphor system.

Gemology of Apatite

• Apatite is occasionally used as a gemstone, with faceted and cabochon-cut varieties.
• Chatoyant apatite stones are known as 'cats-eye apatite.'
• Transparent green apatite stones are known as 'asparagus stone.'
• Blue apatite stones have been called 'moroxite.'
• Major sources of gem apatite include Brazil, Myanmar, Mexico, and several other countries.

Apatite in Thermodynamics and Lunar Science

• The thermodynamic properties of apatite have been studied, including its enthalpies of formation and structural properties.
• Apatite has been found in moon rocks collected during the Apollo program.
• Re-analysis of these samples revealed the presence of water trapped in apatite as hydroxyl, suggesting the existence of water on the lunar surface.
• Estimates indicate that the lunar surface could contain water at a rate of at least 64 parts per billion, 100 times greater than previous estimates.
• If the minimum amount of mineral-locked water were converted to liquid, it would cover the Moon's surface in approximately one meter of water.

Bio-leaching and Apatite Group

• Ectomycorrhizal fungi Suillus granulatus and Paxillus involutus can release elements from apatite.
• Mycorrhizal fungi increase phosphorus uptake in plants through the release of phosphate from apatite.
• Apatite is a prototype of chemically, stoichiometrically, or structurally similar minerals, biological materials, and synthetic chemicals.
• Minerals similar to apatite are known as apatites, such as lead apatite (pyromorphite) and barium apatite (alforsite).
• Apatites have potential uses as pigments, phosphors, and for absorbing and immobilizing toxic heavy metals.

Apatite Data Sources