labradorite

(lăb`rədôrīt', lăbrədôr`īt), a variety of plagioclase feldsparfeldspar
or felspar
, an abundant group of rock-forming minerals which constitute 60% of the earth's crust. Chemically the feldspars are silicates of aluminum, containing sodium, potassium, iron, calcium, or barium or combinations of these elements.
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Labradorite

(named for a deposit on Labrador), a mineral of the soda-lime feldspars—the plagioclases. It is an isomorphic mixture of soda feldspar (albite) with lime feldspar (anorthite). The mineral contains 50–70 percent anorthite. It crystallizes in the triclinic system; it is colorless, white, or gray and forms complex twins, often with an attractive blue-green and golden iridescence. Its hardness is 6 on the Mohs’ scale and its density is 2,680–2,720 kg/m³. Labradorite enters into the composition of many basic magmatic rocks, including gabbros, basalts, and diabases. Rocks consisting almost entirely of labradorite are called labradoritites.

labradorite

[′lab·rə‚dȯ‚rīt]

(mineralogy)

A gray, blue, green, or brown plagioclase feldspar with composition ranging from Ab₅₀ An₅₀ to Ab₃₀ An₇₀, where Ab = NaAlSi₃O₈ and An = CaAl₂Si₂O₈; in the course of formation when the natural material cools, the feldspar sometimes exhibits a variously colored luster. Also known as Labrador spar.

References in periodicals archive ?

Muscovite, albite, labradorite and some calcite (calcium carbonate) were also identified in the X-ray diffraction patterns, Figure 1.

Composicion y morfologia de cabello humano arqueologico y contemporaneo

The crystals show the schiller effect, like labradorite.

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Its range includes: Cappuccino Mocha, Magma Gold, Blue Pearl, Eucalyptus, Alpine Green, Crema San Marco, Verde Fantastic, Juprana Exotica, Indian Green Labradorite and Golden Teak Quartzite.

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Her current collection features an endless variety of semi-precious stones such as Labradorite, Russian Amazonite, Moonstone, and Tiger's Eye, and varies from delicate to chunky pieces to reflect her clientele's taste, personality and characteristics.

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42) In line with architect Shchusev's plans, the entrance to the mausoleum was flanked in black and grey labradorite, (43) with red granite and raspberry-colored quartzite (44) symbolising the red of the Revolution, and black gabbro (45) symbolising mourning.

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There, the gabbros, mostly norite, occasionally troctolite are generally coarse-grained, equigranular to gently pegmatitic, show a texture from cumulate to holocrystalline and are composed by labradorite, augite and subordinate bronzite, with minor amounts of magnetite, ilmenite, and alteration products.

Las rocas intrusivas basicas-ultrabasicas del Complejo Estratificado del Vizcaino y la ofiolita del Vizcaino (Baja California Sur, Mexico)

Bainbridge identifies a number of pieces as being his work, including a grey chalcedony donkey in the Royal Collection and a labradorite owl given by Queen Alexandra to her friend Lady De Grey, the Marchioness of Ripon.

Faberge in London: the discovery in a Moscow archive of unknown photographs of Faberge's shop in London, published here for the first time, reveals much about the role of the great jeweller in Edwardian high society

In the groundmass, there also occur very small plates of plagioclases: labradorite ([An.

New age and petrological constraints on Lower Silesian basaltoids, SW Poland

The core composition for all three types of crystals, as determined mainly by extinction angle methods, is bytownite for units A, C, E and G; labradorite for unit B and oligoclase for unit D.

Characterization of the Alamo Creek Basalt, Big Bend National Park, Texas

Rubies, emeralds, sapphires, topaz, fire opal, garnet, tourmaline, labradorite, moonstone, and black star obsidian, are just a few of the stones available, all set in silver.

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Michele, by contrast, likes to work with tourmaline, agate druse, labradorite and psilomelane.

Leaving no stone unturned; CONSUMING PASSIONS Diamonds might be a girl's best friend, but it's the less precious gems that have won the heart of Michele White. Jo Ind met the Birmingham jewellery maker

Maderne 'Signature' Fine Jewelry presenting show-stopping one-of-a-kind diamond slices and organic gemstones spanning Aquamarine, Black Onyx, Chalcedony, Green Onyx, Labradorite, Lapis Lazuli, and Rainbow Moonstone surrounded by the most exquisite micro-pave diamond detail and set in 14k white, yellow or rose gold.

J. Maderne Fine Jewelry Unveils Exquisite One-of-a-Kind Designs for the Everyday Fashion-Forward Woman