1 Dec 2010 Buddington (1939) classified the Adirondack anorthosites on their plagioclase to mafic mineral content as anorthosite (>90% plagioclase and <10

Anorthosite, type of intrusive igneous rock composed predominantly of calcium-rich plagioclase feldspar. All anorthosites found on Earth consist of coarse crystals, but some samples of the rock taken from the Moon are finely crystalline. Most anorthosites formed during Precambrian times.

Anorthosite is by definition an igneous rock consisting of 90-100% plagioclase feldspar. When the amount of mafic minerals exceeds 10 % the name leucogabbro or anorthositic gabbro (alternatively -norite) is commonly used, depending on the nature of the pyroxene. Anorthosite - A core 3.5cm wide of the rock type called "anorthosite", which are composed mostly of calcic plagioclase with also some mafic rock. A considerable amount of rocks brought back by the Apollo missions were anorthosite. It is not a common rock type and is found in few places on Earth, but common on the Moon's surface. .

Feldspar is a very common mineral and occurs in virtually all igneous rocks, but rocks containing 90%+ calcium feldspar are less common. Anorthite is the calcium endmember of the plagioclase feldspar mineral series. The chemical formula of pure anorthite is Ca Al 2 Si 2 O 8. Anorthite is found in mafic igneous rocks. Anorthite is rare on the Earth but abundant on the Moon.

About Anorthosite Hide A coarse-grained crystalline rock consisting mostly of calcic plagioclase (>90%, usually labradorite) with <10% mafics.

Unlike the barren anorthosite with unzoned plagioclase, the mineralized anorthosites of the “South Reef” are characterized by pronounced zonation of cumulus plagioclase, showing distinct brown rims that have a similar compositions to plagioclase rims from the overlying cumulate [ 9 ].

Minerals and Rocks Series Volume 21. xix + 422 pp.

Anorthosite is by definition an igneous rock consisting of 90-100% plagioclase feldspar. When the amount of mafic minerals exceeds 10 % the name leucogabbro or anorthositic gabbro (alternatively -norite) is commonly used, depending on the nature of the pyroxene.

Minerals And Gemstones Crystals Minerals Today it is the majority shareholder of Greenland Anorthosite Resources which discovered a large anorthosite deposit on the country’s west coast. The mineral found there is particularly attractive given the rarity of its low-alkali content making it a more valuable, greener choice for use by fibreglass manufacturers and in aluminium production. Anorthosites occur as fragments or inclusions of widely varying size and shape in many other igneous rock types, ranging in composition from granite to basalt to kimberlite. Anorthosite is by definition an igneous rock consisting of 90-100% plagioclase feldspar. When the amount of mafic minerals exceeds 10 % the name leucogabbro or anorthositic gabbro (alternatively -norite) is commonly used, depending on the nature of the pyroxene. Rock densities can provide valuable information on modes, especially where plagioclase and a mafic phase are the dominant minerals, as shown by Morse (1979a) for troctolites in the Kiglapait intrusion and by Cawthorn & Spies for pyroxenite to anorthosite packages in the Critical Zone of the Bushveld Complex. 2020-02-21 · Strictly speaking, the name “anorthosite” is applied to a rock composed of 90 to 100 of calcium-rich plagioclase feldspar and small amounts of high temperature minerals like pyroxene, olivine, magnetite (Fe3O4) or ilmenite (FeTiO3).

Anorthosite / ænˈɔr / is a phaneritic, intrusive igneous rock characterized by a predominance of plagioclase feldspar (90–100%), and a minimal mafic component (0–10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present. - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties).
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2012-12-01 A Deposit Model for Magmatic Iron-Titanium-Oxide Deposits Related to Proterozoic Massif Anorthosite Plutonic Suites. By Laurel G. Woodruff, Suzanne W. Nicholson, and David L. Fey The minerals of the anorthosite and the secondary minerals formed by its replacement are described. INTRODUCTION The titanium deposits of the Roseland distr'ot, Nelson and Amherst Counties, have long supplied most of the rutile used in the world, and the district also … December 23, 2014 New 2016 reference added.

. This and many more mineral specimens are available for sale at Stillwater Anorthosite contains numerous sulfides contianing PGE's (Platinum Ground Elements) Stillwater Anorthosite Mineral # 710 another view Click on the mineral to enlarge the specimen, in the center and going down from there you can see what looks like pyrite. Those are the sulfides containing the PGE's.
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Anorthosite / ænˈɔːrθəsaɪt / is a phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal mafic component (0–10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present.

Some can be demonstrated to be xenolithic, and represent fragments of other anorthosite types incorporated into ascending magmas. Others, however, are cognate, and represent accumulations of plagioclase from their host magmas. Anorthosite is an almost monomineralic, feldspathic rock with a great variety of industrial applications (Table 1).