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Gemstones 250x250

The apatite Mineral Group

Yellow Gemmy Apatite

Apatite is named for the Greek word apate, which means "deceit", since Apatite is similar in appearance to many other minerals. Apatite describes a group of similar isomorphous hexagonal phosphate minerals. The primary Apatite group includes Fluorapatite, Chlorapatite, and Hydroxylapatite. The extended Apatite supergroup describes additional minerals such as Pyromorphite, Mimetite, and Vanadinite, but these are described individually in this guide.

It can be difficult to distinguish between individual members of the primary Apatite group. A designation of the specific Apatite type is not usually made, being called simply "Apatite" by collectors and dealers. However, most of the fine crystals and collector specimens are of the Fluorapatite type, which is by far the most common form of Apatite.

Apatite is the most common phosphate mineral, and is the main source of the phosphorus required by plants. The bones and teeth of most animals, including humans, are composed of calcium phosphate, which is the same material as Apatite. (These biological Apatites are almost exclusively the Hydroxylapatite type.)

Chemical Formula

Apatite is mineral group with the following chemical formula applied to the most common members of the primary group (excluding the extended Apatite supergroup):
Ca5(PO4)3(F,Cl,OH)

Individual Apatite minerals are:
Fluorapatite - Ca5(PO4)3F
Chlorapatite - Ca5(PO4)3Cl
Hydroxylapatite - Ca5(PO4)3OH

Color

Colorless, white, yellow, brown, gray, red, pink, purple, blue, green. Some specimens are multicolored.

Crystal System

Hexagonal

Properties

Streak
White
Hardness
5
Transparency
Transparent to translucent
Specific Gravity
3.1 - 3.2
Luster
Vitreous
Cleavage
Indiscernible
Fracture
Conchoidal
Tenacity
Brittle
Other ID Marks
1) Specimens from certain localities will fluoresce orange yellow in shortwave ultraviolet light.
2) Thermoluminescent bluish-white.

Crystal Habits

(The hexagonal crystal system designation is due to a hexagonal symmetry of most Apatite. However, positional ordering of chlorine atoms or the hydroxyl radical in Chlorapatite and Hydroxylapatite can lead to monoclinic symmetry.)

Apatite generally forms as well-shaped hexagonal crystals, which may be prismatic, dipyramidal, and stubby. Also as flat, tabular plates, columnar, in stacked parallel growths, as globular masses, acicular, grainy, stalactitic, botryoidal, and earthy. Also in enormous beds of massive material, from which industrial phosphorus is mined.

3D Crystal Atlas

Additional Information

Composition
Apatite group - Calcium fluoro-chloro-hydroxyl phosphate

Common Individual Group Members:
Fluorapatite - Calcium fluoro-phosphate
Cholorapatite - Calcium chloro-phosphate
Hyldroxylapatite - Basic calcium phosphate
In Group
Phosphates; True Phosphates; Apatite Group
Striking Features
Hardness and crystal form
Environment
As gemmy crystals in granite pegmatites; in hornfels in contact metamorphic rocks; in igneous diabase environments; in ore veins, and in nepheline syenite pegmatites.
Rock Type
Igneous, Metamorphic

Varieties

 -   Variety of the Apatite group where the phosphate radical (PO4) is partially replaced by a carbonate radical (CO3). It has a chemical formula of Ca5(PO4,CO3)3(OH,F). Also known as Carbonate-rich Apatite.
 -   Individual member mineral of the Apatite group with chlorine being dominant in its structure. For a short period of time, it was renamed by the IMA as Apatite-(CaCl), but is now again favored again as Chlorapatite.
 -   Microcrystalline variety of botryoidal white Apatite.
 -   Individual member mineral of the Apatite group with fluorine being dominant in its structure. For a short period of time, it was renamed by the IMA as Apatite-(CaF), but is now again favored again as Fluorapatite.
 -   Individual member mineral of the Apatite group with hydroxyl being dominant in its structure. For a short period of time, it was renamed by the IMA as Apatite-(CaOH), but is now again favored again as Hydroxylapatite.
 -   Manganese-rich variety of Apatite.
 -   A strontium-rich form of Apatite containing some rare earth elements, described from Lovozero in the Kola peninsula of Russia.
 -   A botryoidal variety of Apatite, originally described from Staffel, Hesse, Germany.
 -   Rare, strontium-rich variety of Apatite, with the calcium partially replaced by strontium. Its chemical formula is (Sr,Ca)5(PO4)3(OH,F).

Uses

Apatite is the main source of phosphorus. Phosphorus was previously extracted from crystalline Apatite, but nowadays is extracted from enormous deposits of Apatite-rich rock. Apatite is essential in the manufacture of phosphate fertilizers, and is very important in the chemical and pharmaceutical industries. Apatite is also a popular collectors mineral, and some transparent specimens are faceted for collectors. The gemmy violet and reddish forms are very much valued by collectors and command high prices.

Noteworthy Localities

The vast majority of collector specimens are of the Fluorapatite type, thus the localities described here are generally for Fluorapatite. As this mineral is very common, only the most important of Apatite localities are described here.

Important Apatite localities in Europe include Ehrenfriedersdorf, in the Erzgebirge, Saxony, Germany, a classic locality which is also the type locality for this mineral. Panasqueira, Portugal, is well-known for its thick and gemmy tabular Apatite crystals.

Deep blue crystals come from Sludyanka, in Lake Baikal area, Russia; and interesting forms, especially botryoidal, come from the Lovozero Massif, Kola Peninsula, Russia. Purple Apatite comes from the Mawi Pegmatite, Nuristan (Laghman) Province, Afghanistan; and pink and red crystals from Pakistan in the Hunza Vallery, Gilgit; and at Skardu at Shengus, Dassu, and the Shigar Valley. Beautiful greenish-yellow Apatite with a excellent luster and transparency have been coming from the Imichil area in Morocco.

In Brazil, deep blue Apatite crystals come from Ipira, Bahia; and the state of Minas Gerais has several outstanding occurrences such as the Sapo mine, in Conselheiro Pena; Golconda, in Governador Valadares; Pederneira, in Sao Jose da Safira; and Galileia. A pink Apatite has recently come from the La Marina Mine, Boyaca, Colombia. One of the most famous localities of Apatite is Cerro de Mercado, Durango, Mexico, where gemmy prismatic crystals are plentiful.

In Canada, large glassy Apatite crystals in orange Calcite have come from the Yates mine, Otter Lake, Quebec. Very large crystals also come from Ontario, at Bear Lake in Tory Hill, and at Cardiff, both in Haliburton Co.

In the U.S., the state of Maine has several excellent Apatite localities. Beautiful violet crystals come from the Mount Apatite area (especially the Pulsifier Quarry in Auburn, and the Mt. Rubellite Quarry in Hebron,) Androscoggin Co. Also in Maine are the Noyes Mountain Quarry (Harvard Quarry) and the Emmons Quarry, Uncle Tom Mt, both in Greenwood, Oxford Co.

In New Hampshire, Apatite was found in the Palermo No. 1 Mine, Groton, Grafton Co. The Acushnet Quarry in Bristol Co., Massachusetts, produces an aesthetic association of transparent Apatite associated with sparkling dark Chlorite. Good specimens were once found in the Strickland Quarry, Portland, Middlesex Co., Connecticut.

Large opaque Apatite crystals, usually light blue in color, have come from Franklin, Ogdensburg (Sterling Hill), and Hamburg, all in Sussex Co., New Jersey; and across the state line in Amity, Orange Co., New York. Beautiful pink and purple crystals with excellent transparency have come from the Foote Mine, Kings Mountain, Cleveland Co., North Carolina.

Prismatic green Apatite crystals, closely resembling Tourmaline, come from the Himalaya Mine, Mesa Grande, San Diego Co., California. Light blue crystals have come from the Butte mining district, in Silver Bow Co., Montana; and large yellow crystals from the Fulford District, Eagle Co., Colorado and Iron Mountain, Iron Co., Utah. 

Common Mineral Associations

Quartz, Feldspar, Calcite, Magnetite, Muscovite, Phlogopite, Nepheline, Diopside

Distingushing Similar Minerals

Beryl, Tourmaline, and Quartz - Greater hardness.
Calcite - Lower hardness, effervescent in acid.
Pyromorphite, Mimetite, and Vanadinite - Slightly softer and usually occur in distinct localities.


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