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Apetite

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About Apetite - History and Introduction

Historical values 2005 - 2016  Not Available

Apatite

Colour: green, greenish yellow, blue, violet

Hardness: 5

Refractive index: 1.60 - 1.67

Density: 3.17 - 3.35

Chemical composition: Phosphate composition

Crystal structure: hexagonal

Lustre: vitreous

Origins: Mexico, USA, Canada, Madagascar, Spain, Russia, Sri Lanka, India, Burma.

Due to its insufficient hardness the stone is rarely used in jewelry production. However collectors do appreciate intensely coloured blue and violet stones. Apatites are very heat sensitive.

Color

Color Description; Occurrence

1 ct.

3 ct.

5 ct.

10 ct.

30 ct.

130 - medium light very strongly greenish Blue; strong

Alternative name, occurrence category: Common

135.70

146.23

156.76

183.10

No data

113 - medium light very strongly bluish Green; very slightly greyish

Alternative name, occurrence category: Common

101.65

109.54

117.43

137.15

No data

098 - medium bluish Green; very slightly greyish

Alternative name, occurrence category: Common

108.14

116.54

124.93

145.92

No data

087 - medium Green; slightly greyish

Alternative name, occurrence category: Common

47.37

51.05

54.72

63.92

No data

068 - medium yellowish Green; very slightly greyish

Alternative name, occurrence category: Common

28.01

30.19

32.36

37.80

No data

063 - light yellowish Green; very slightly greyish

Alternative name, occurrence category: Common

24.23

26.11

27.99

32.69

No data

055 - light greenish Yellow; strong

Alternative name, occurrence category: Common

21.69

23.37

25.05

29.26

No data

About Apatite - History and Introduction

Apatite is a group of phosphate minerals which includes hydroxyl-apatite, fluor-apatite and chlor-apatite. Apatite is the most common type of phosphate in the world and it is the main source for phosphorus, a chemical essential to bioenergetics and photosynthesis. Apatite is composed of calcium phosphate, which is the same material that makes up teeth and bones.


Although apatite is a very common mineral, transparent gemstone-quality apatite is extremely rare. Despite apatite being the defining mineral for 5 on the Mohs scale of mineral hardness, it remains virtually unknown to most consumers and is seldom found in jewelry stores. However, because apatite occurs in such a wide variety of attractive colours and forms, it is a favourite among gemstone collectors. Connoisseurs often seek out rare colours such as Paraiba-like blue-green apatite or leek-green apatite, which is known as 'asparagus stone'. Deep purple, violet and reddish specimens are also sought after. There is an additional blue variety known as 'moroxite', but this is typically heat-treated to enhance colour.


The word 'apatite' was derived from a Greek word meaning 'cheat'. The name was given to apatite because of its close resemblance to several other precious gemstones. As a result of many people being 'cheated', apatite became unfairly labeled as the 'deceitful stone'. Amblygonite, andalusite, brazilianite, precious beryl, sphene, topaz and tourmaline can all be confused with apatite.


Apatite Chatoyancy

Apatite that exhibits chatoyancy, or a cat's eye effect, is extremely rare. Cat's eye apatite gemstones are always cut en cabochon. Chatoyancy is a rare optical phenomenon existing only in a handful of different gem types. It is distinguished by a unique light reflection that resembles the slit eye of a cat. It is caused by light reflected off parallel inclusions within a gemstone, typically rutile needles, fibres or channels. Cat's eye reflections are best viewed in direct light; when the stone is rotated, the cat's eye will appear to glide across the surface.


Apatite Mineralogy

Apatite develops as crystals within granite pegmatites, metamorphic rocks and igneous environments. Apatite crystal can vary in composition based on the level of hydroxide, fluorine or chlorine ions. Apatite-rich rocks are one of the most important sources for phosphorus. Not only is phosphorus required by plants, but it is also an essential chemical commonly used in fertilizers, explosives, fireworks, pesticides, toothpaste, detergents and pharmaceutical products.


Apatite can be identified through several testing methods. Fluorescence is one way to distinguish apatite specimens. Apatite is much harder than calcite, and because it is softer than tourmaline, beryl and quartz, a simple scratch test can usually identify and distinguish apatite. Apatite value depends mostly on colour saturation. Specimens with high color intensity are considered most valuable. Gem-quality apatite is rarely found in large sizes; stones over one carat can command very high premiums. Apatite is a 'Type II - Typically Included' gem type. Almost all apatite will have visible inclusions. Eye-clean specimens are very rare, especially in larger sizes.


Apatite Origin and Gemstone Sources

Apatite is found in a number of places in the world, including Myanmar (Burma), India, Kenya, Brazil, Norway, Sri Lanka, South Africa, Mexico, Canada and the United States.


Buying Apatite and Determining Apatite Gemstone Value

Apatite Colour


The range of colors include colorless, pink, yellow, green, blue and violet. A rare variety is a rich purple from Maine. Blue Brazilian stones are second in demand. Madagascar is known to produce a neon blue-green material that is highly desirable. Light-green apatite carries the trade name 'asparagus stone'. The color of the best specimens of apatite can rival famed Paraiba tourmaline. As for any other gem, color saturation defines the value.


Apatite Clarity and Lustre


When cut and polished, apatite has a vitreous lustre. Gem-quality apatite typically occurs transparent, but translucent specimens do exist.


Apatite Cut and Shape


Apatite comes in many different shapes and cuts. Transparent specimens are typically faceted into traditional shapes. Fancy shapes and calibrated sizes are hard to find and command higher prices. Some blue and yellow apatite exhibits chatoyancy and is cut and polished as cat's eye apatite. Specimens with bases parallel to the fibers are most ideal for cabochon cuts.


Apatite Treatment

Apatite gemstones are typically untreated. Blue apatite is known to be heat-treated, but some are un-enhanced. Most green specimens are typically untreated. Gemstone suppliers should always disclose treatments and enhancements made to their gemstones for sale.

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