Plagioclase is a very important series of tectosilicate minerals within the feldspar family.
Plagioclase
Another name for Oligoclase.
Plating
Plating or electroplating (also called Galvanotechnics after its inventor, Luigi Galvani) is a process in which one metal is coated with another metal using electricity.
Plagioclase: Another name for Oligoclase.
Platinum: One of the three "precious metals" along with gold and silver, platinum is the rarest of them all.
PLAGIOCLASE:
Series from albite (NaAlSi3O8) through anorthite
(CaAl2Si2O8) and includes:
Albite ...
Plagioclase - triclinic(often flat or tabular with striations)
Color:
Orthoclase - usually light colored white, pink, yellow, or cream, and not transparent. The gem variety is clear to pale yellow, and some called "noble orthoclase" ...
Plagioclase A triclinic mineral with the general chemical composition of Al2Si2O8
Pyroxene One of a number of 5i04 silicate minerals common in meteorites
Top ...
Plagioclase Feldspar Group
The Plagioclase series is a group of related feldspar minerals that basically have the same formula but vary in their percentage of sodium and calcium.
Platy plagioclase feldspar caused by foliation
Hydrothermal activity can cause chemical alteration of rock in a process called metasomatism.
SilicatePlagioclase
CaAl2Si2O8
Other names/forms:
Anothite (Ca), Albite (Na) ...
Labradorite Is the plagioclase feldspar that is most commonly faceted as a gemstone. It may be orange, yellow, colorless, or red, but the material that shows a play of color, or "schiller," is the most popular for use in jewelry.
plagioclase twinning Two or more crystals that twin in a repeated pattern ("repeated twinning") as depicted in the figure below. Named after the mineral Plagioclase, which most frequently exhibits this form of twinning.
This brilliantly iridescent material is regarded as the world's most beautiful form of labradorite (a variety of plagioclase feldspar). Specifically, "spectrolite" is a trade name for high-grade labradorite found only in Finland.
Prior to the finds of substantial amounts of facetable plagioclase feldspar crystals in Oregon, most sunstone, much of which came from India, was opaque and used for cabbing, bead, or carving material. Such is the case no longer.
- In places the upper edges of the Cambiado strata grade into a granular, grayish rock in which laths of plagioclase feldspar from 1 to 3 mm. in length are thickly set in a greenish-black ground.
Labradorite (a variety of plagioclase feldspar) is a fairly abundant grayish mineral that has brilliant flashes of color (usually green, blue or red) after it is polished (called labradorescence). The crystals are transparent to translucent.
The pegmatite consists of smoky quartz, perthite, massive plagioclase, cleavelandite, garnet, beryl and traces of lepidolite and columbite-tantalite.
The stone belongs to the plagioclase feldspar group, which is a series of mixtures of sodium and calcium aluminum silicates. It was discovered in 1940 during World War II by accident.
Labradorite is a smoky gray stone that is plagioclase feldspar. It is found in the U.S, Canada, Mexico, Ukraine, and Australia. A metallic rainbow reflection is seen from different angles.
Basic igneous rocks (BIR) include basalts, dolerites, gabbros, kimberlites, and peridotites, and abundant minerals in such rocks include olivine, pyroxenes, Ca-feldspar (plagioclase), amphiboles, and biotite.
Spectrolite is another name for Finnish Labradorite (a variety of plagioclase feldspar). It is a fairly abundant grayish mineral that has brilliant iridescent flashes of color (usually green, blue, orange, or red) after it is polished.
This precious gem is a form of Oligoclase feldspar which is itself a variety of plagioclase feldspar. The Sunstone gem displays different kinds of colors due to inclusions.
In the plagioclase structures, the amount of tetrahedral Al varies in proportion to the relative amounts of Ca2+ and Na+; but not as to maintain electrical neutrality; the more Ca2+, the greater the amount of Al3+".
Found in pockets where plagioclase altered to clay; could be scooped out by hand. Mines were thought to be essential depleted(?) by 1925, when mining was greatly curtailed.
Igneous rock composed almost wholly of the mineral plagioclase feldspar.
Assay
The analysis of the proportions of metals in ore, or the testing of an ore or mineral for composition, purity, weight, or other properties of commercial interest.
Oligoclase: (Also called Plagioclase) A triclinic feldspar made of soda-lime.
Olivelia Shells: A kind of seashell used for Heishi necklaces.
Olivine: See Chrysolite and Peridot.
A number of minerals crystallize in the -1 class including plagioclase feldspar pectolite, microcline, and wollastonite. The second symmetry class of the triclinic system is the 1, which is equivalent to no symmetry! ...
Black Moonstone: A black moonstone is actually a labradorite [a type of plagioclase feldspar]- a grayish mineral that shows flashes of color, usually green, blue or red after being polished.
Black Onyx: An onyx with a dark opaque body.
orthoclase (embracing moonstone and adularia) and microcline (embracing amazonstone)
plagioclase (embracing sunstone, aventurine, feldspar, labradorite, and peristerite)
celsian; each with several intermediate series ...
Basalt: A dark volcanic rock, often with a glassy appearance, composed chiefly of plagioclase, pyroxene, and olivine.
Base Metal: The collective term for any and all non-precious metals.
It is essentially a silicate of alumina and soda. Scapolite is also called Wernerite, named after the German Geologist A.G. Werner. Scapolite is typically an altered form of plagioclase feldspars found in metamorphic rocks.
Crystals of this system possess no mirror planes. The holomorphic class demonstrates a center of inversion symmetry.
Mineral species of the triclinic class include plagioclase and axinite; these species tend to be of tabular habit.
 See also: Crystal, Mineral, Color, Stone, Minerals
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