Feldspar definition, any of a group of minerals, principally aluminosilicates of potassium, sodium, and calcium, characterized by two cleavages at nearly right angles: one of the most important constituents of igneous rocks. See more.
feldspar (fĕl´spär, fĕld´–) or felspar (fĕl´spär), 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.
Feldspars are hard minerals, all of them with a hardness of 6 on the Mohs scale. This lies between the hardness of a steel knife (5.5) and the hardness of quartz (7). In fact, feldspar is the standard for hardness 6 in the Mohs scale.
Feldspar - Chemical composition: All the rock-forming feldspars are aluminosilicate minerals with the general formula AT4O8 in which A = potassium, sodium, or calcium (Ca); and T = silicon (Si) and aluminum (Al), with a Si:Al ratio ranging from 3:1 to 1:1. Microcline and orthoclase are potassium feldspars (KAlSi3O8), usually designated Or in discussions involving their end-member composition.
Feldspars are found in the every section of the rock cycle. Many feldspars are igneous as they commonly precipitate out in magma as it cools. They may also be formed as metamorphic minerals in veins of other rocks. This process involves both heat and pressure. Finally, over time feldspar can weather to produce sediments.
Define feldspar. feldspar synonyms, feldspar pronunciation, feldspar translation, English dictionary definition of feldspar. also fel·spar n. Any of a group of abundant rock-forming minerals occurring in igneous, metamorphic, and sedimentary rocks, and consisting of silicates of...
More correctly Feldspar is the name of a group of minerals the Feldspars. This confuses beginners Ruskin 04:51, 14 April 2017 (UTC) abundance. Currently the quartz page says that quartz is the second most abundant mineral (in the earth's crust) after feldspar.
Feldspar is one of the most abundant minerals in the earth's crust. The feldspars include a range of compositions with a general chemical formula of xAl(Al,Si) 3 O 8 where x can be sodium (Na) and/or calcium (Ca) and/or potassium (K). They are primarily used in glass and ceramics making.
Feldspars are popular because they are one of the most abundant minerals on Earth. They are present in a variety of habits and are found in a tremendous array of environments and there are many collecting sites where good feldspar crystals can be found.
Feldspar: Feldspar, any of a group of aluminosilicate minerals that contain calcium, sodium, or potassium. Feldspars make up more than half of Earth's crust, and professional literature about them constitutes a large percentage of the literature of mineralogy. Learn more about the properties and uses of feldspar in this article.
Primary Commodity Uses: Feldspar is one of the most common minerals on the planet and is mostly used for glassmaking and ceramics. ... Feldspars are aluminosilicates containing varying amounts of calcium, potassium, or sodium. In glassmaking, feldspar provides alumina for improving hardness, durability, and resistance to chemical corrosion.
3.6.2 Feldspars. Feldspars are especially common minerals and make up about 60% of the Earth's crust. They crystallise from a wide spectrum of magmas and are found in many metamorphic and sedimentary rocks. The name 'feldspar' refers to a group of silicate minerals that share the same basic structure. The three most important feldspar minerals are orthoclase (KAlSi 3 O 8), albite (NaAlSi 3 …
May 01, 2018· Feldspar definition is - any of a group of crystalline minerals that consist of aluminum silicates with either potassium, sodium, calcium, or barium and that are an essential constituent of nearly all crystalline rocks.
Most of the products we use every day are made with feldspar, the most abundant group of minerals in the earth's crust. Feldspars play an important role as fluxing agents in ceramics and glass production, and are also used as functional fillers in the paint, plastic, rubber and adhesive industries.
Alkali feldspars have a range of chemical composition and the end members may be written as KAlSi 3 O 8 and NaAlSi 3 O 8.The K-feldspar polymorphs, sanidine, orthoclase, microcline, and adularia have identical chemical compositions.Sanidine is a monoclinic alkali feldspar with small optic axial angle (2V) and commonly occurs in volcanic rocks. Orthoclase is a monoclinic alkali feldspar that ...
Feb 24, 2018· Feldspars are a group of minerals having a crystalline form. These are one of the most abundant minerals found in the Earth's crust. Read, in this ScienceStruck post, about the types, uses, characteristics, and properties of this crystalline compound.
Production and Uses of Feldspar Minerals. About 20 million tonnes of feldspar have been produced in 2010, primarily by three countries: Italy (four.7 Mt), Turkey (4.Five Mt), and China (2 Mt) Feldspar is a common uncooked fabric utilized in glassmaking, ceramics, and to a point as a filler and extender in paint, plastics, and rubber.
The feldspar group is a fairly large group with nearly 20 members recognized, but only nine are well known and common. Those few, however, make up the greatest percentage of minerals found in the Earth's crust. The following are some of the more common feldspar minerals: The plagioclase feldspars: Albite, (Sodium aluminum silicate)
Feldspar is the most abundant mineral group in the Earth's crust.There are more feldspars (60%) than all the other minerals combined in the outer (13-17) km of the crust 1.Feldspars occur in most igneous and metamorphic rocks.
Potassium feldspars are the feldspar minerals in which the silicate tetrahedral and aluminum tetrahedra are bound with potassium ions, rather than sodium or calcium ions as in the plagioclase feldspar subgroup. The potassium feldspar group is composed of three mineral polymorphs, each having the same chemical composition, but slightly different ...
Brown, W.L. and Parsons, I. (1984) The nature of potassium feldspar, exsolution microtextures and development of dislocations as a function of composition in perthitic alkali feldspars. Contributions to Mineralogy and Petrology: 86: 335-341.
Feldspars are a group of closely related minerals that together make up the majority of the Earth's crust. All of them have a hardness of 6 on the Mohs scale, so any glassy mineral that's softer than quartz and cannot be scratched with a knife is very likely to be a feldspar.
Physical Properties of Plagioclase Minerals. All feldspar minerals have two directions of perfect cleavage. It is usually easy to distinguish plagioclase feldspars because their two planes of cleavage intersect at 90-degree angles, and their cleavage faces often display striations.
feldspar (countable and uncountable, plural feldspars) Any of a large group of rock-forming minerals that, together, make up about 60% of the earth's outer crust. The feldspars are all aluminum silicates of the alkali metals sodium, potassium, calcium and barium. Feldspars are the principal constituents of igneous and plutonic rocks.
Feldspar is by far the most abundant group of minerals in the earth's crust, forming about 60% of terrestrial rocks. Most deposits offer sodium feldspar as well as potassium feldspar and mixed feldspars. Chemically, the feldspars are silicates of aluminium, containing sodium, potassium, iron, calcium, or barium or combinations of these elements.
Plagioclase: Plagioclase ((Ca,Na)AlSi 3 O 8) is one of the forms of feldspar.It is an aluminum-containing silicate.This feldspar is distinguished from the orthoclase form by its content of calcium and sodium.. The feldspars are the most abundant minerals on the earth.