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Gemstones 250x250

The Mineral lazulite

Perfect Bipyramidal Lazulite

Lazulite is an aesthetic blue mineral that forms in distinct crystals. Its name is very similar and often confused with Lazurite, which is an entirely different mineral species. However, the names of both these minerals are derived from the term "Lazaward", which means heaven in Arabic, alluding to their blue color.

Lazulite forms a series with the rare mineral Scorzalite, which is the iron-rich equivalent of Lazulite.

Chemical Formula

(Mg,Fe)Al2(PO4)2(OH)2

Color

Dark indigo-blue to almost black, sky-blue, light blue, grayish-blue, and greenish-blue. May also have intermixed white or creamy streaks or splotches, or be multicolored blue and blue-green. Transparent Lazulite is pleochroic.

Crystal System

Monoclinic

Properties

Streak
White
Hardness
5.5 - 6
Transparency
Transparent to opaque
Specific Gravity
3.0 - 3.1
Luster
Vitreous to dull
Cleavage
3,1
Fracture
Uneven
Tenacity
Brittle

Crystal Habits

Crystal habits include steep bipyramidal or wedge-shaped crystals. Crystals are usually small and embedded in a matrix. Also tabular, in dense crystal masses, in aggregates of distorted or damaged crystals, grainy, and massive. Crystals are sometimes etched, and occasionally twinned.

3D Crystal Atlas

Additional Information

Composition
Basic phosphate of magnesium, iron, and aluminum
In Group
Phosphates; True Phosphates
Striking Features
Color and crystal habits
Environment
In metamorphosed schists, hydrothermal replacement deposits, and igneous pegmatite dikes.
Rock Type
Igneous, Metamorphic

Uses

Lazulite is a popular collectors mineral, and specimens from Graves Mountain (Georgia) and Rapid Creek (Yukon) are especially desirable. Specimens embedded in white Quartz, especially those from Austria, are sometimes sliced into slabs or polished for collectors. Lazulite is occasionally used a minor collectors gemstone.

Noteworthy Localities

One of the most famous localities for Lazulite is Graves Mountain, Lincoln Co., Georgia, which produced well-formed blue crystals embedded in a crumbly Quartz matrix. The locality of Rapid Creek (and nearby Crosscut Creek), in the Yukon Territory of Canada is also well-known for its outstanding transparent dark blue Lazulite crystals.

Austria is a classic producer of Lazulite, with the noteworthy localities of Fischbach, in Styria; and Werfen, in Salzburg. In Italy, Lazulite comes from the Vizze pass, Bolzano Province; and from Monte Folgorito, Pietrasanta, Lucca Province. Exceptionally large and gemmy distorted crystals came from Laila, Gilgit District, Pakistan.

Other U.S. occurrences are the Champion Mine, Mono Co., California; and North Groton, Grafton County, New Hampshire.

Common Mineral Associations

Quartz, Hematite, Muscovite, Pyrophyllite, Siderite, Topaz, Augelite, Wardite

Distingushing Similar Minerals

Lazurite - Different crystal habit, has a blue streak and lower specific gravity.
Scorzalite - Difficult to distinguish, though usually darker in color and higher specific gravity.
Sodalite - Difficult to distinguish, though usually has white veins and strong fluorescence.


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