Daniel Blakemore

Mineral Spotlight: Apatite

Apatite is one of the most important minerals in modern society, yet many people are unaware of its incredible utility. Apatite is not a single mineral species but a large supergroup of around 40 distinct mineral species. Although the apatite group is large, the most commonly thought of apatite minerals are the calcium phosphates, which have the composition Ca5(PO4)3(Cl,F,OH). The calcium phosphate apatites form an unusual anion solid solution series, where chlorine, fluorine and hydroxyl ions can substitute for each other. The incredible amount of elements that can substitute in the crystal structure of apatite make it one of the most important minerals to humans on the planet.

Probably the most obvious way humans have used apatite is as an ore of phosphate (PO4). Phosphate has critical applications in modern society, but none more important than in fertilizer, which helps sustain global food supply. While phosphate fertilizers can harm aquatic life when runoff into bodies of water, they contribute to food production for the world.

Apatite minerals are also used industrially in optics as phosphors for fluorescent lights, and in lasers.

Apatite plays a unique role in biology as well. Your teeth and bones are made up of materials similar in crystal structure to apatites. Studying apatite therefore has direct implications in medicine and dentistry.  

The wide array of elements, both common and unusual, that substitute into apatite’s crystal structure lead to exciting potential for environmental remediation. Apatites are being studied and implemented for cleaning soils contaminated with radioactive nucleotides, and to help reduce the radiotoxicity of spent nuclear fuel.

As a scientific tool and geologic timepiece, apatite is extremely useful. Radioactive elements such as uranium and thorium incorporated into the crystal structure of apatite can be dated to obtain the absolute age of the mineral.

In addition to all these practical uses of apatite, the apatite minerals can achieve spectacular colors and some are commonly used as gemstones. Also, apatite is commonly fluorescent due to the inclusion of particular trace elements.

Come learn more about minerals by visiting the Dice Mineralogical Museum, located on the first floor of North Hall, and open this semester on Wednesdays, Thursdays and Fridays from 12:30 to 4 p.m.