Amblygonite

Amblygonite is a fluorophosphate mineral, (Li,Na)AlPO4(F,OH), composed of lithium, sodium, aluminium, phosphate, fluoride and hydroxide. The mineral occurs in pegmatite deposits and is easily mistaken for albite and other feldspars. Its density, cleavage and flame test for lithium are diagnostic. Amblygonite forms a series with montebrasite, the low fluorine endmember. Geologic occurrence is in granite pegmatites, high-temperature tin veins, and greisens. Amblygonite occurs with spodumene, apatite, lepidolite, tourmaline, and other lithium-bearing minerals in pegmatite veins. It contains about 10% lithium, and has been utilized as a source of lithium. The chief commercial sources have historically been the deposits of California and France.
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Noun
1. a white or gray mineral consisting of lithium aluminum phosphate; a source of lithium
(hypernym) mineral
(substance-meronym) lithium, Li, atomic number 3

n. amblygonite

General Information:
 Chemical Formula:
(Li,Na)Al(PO4)(F,OH)
 Composition:
(Molecular Weight = 151.41 gm)
Sodium 3.80 % Na
Lithium 3.44 % Li
Aluminum 17.82 % Al
Phosphorus 20.46 % P 
Hydrogen 0.17 % H 
Oxygen 44.91 % O 
Fluorine 9.41 % F 
 Empirical Formula:
Li0.75Na0.25Al(PO4)F0.75(OH)0.25
 Name Origin:
From the Greek amblys - "blunt" and goni - "angle."
Physical Properties:
 Cleavage:
[100] Perfect, [110] Good, [011] Distinct
 Color:
white, yellow, gray, bluish gray, or greenish gray.
 Density:
2.98 - 3.11, Average = 3.04
 Diaphaniety:
Transparent to Subtransparent to translucent
 Habits:
Columnar - Forms columns, Euhedral Crystals - Occurs as well-formed crystals showing good external form., Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
 Hardness:
5.5-6 - Knife Blade-Orthoclase
 Luminescence:
None.
 Luster:
Vitreous - Pearly
 Streak:
white
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AMBLIGONITE