What elements make up plagioclase feldspar?

Asked By: Christena Lischenko | Last Updated: 14th April, 2020
Category: science geology
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The feldspars are a family of silicate minerals which occur in igneous rocks. There are many different members to the feldspar group. Obviously, silicon and oxygen form the foundation for the group, but calcium, sodium, and potassium are also present.

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In respect to this, what are the elements of feldspar?

The mineralogical composition of most feldspars can be expressed in terms of the ternary system Orthoclase (KAlSi3O8), Albite (NaAlSi3O8) and Anorthite (CaAl2Si2O8). Chemically, the feldspars are silicates of aluminium, containing sodium, potassium, iron, calcium, or barium or combinations of these elements.

Furthermore, what minerals are in plagioclase feldspar? The Plagioclase series is a group of related feldspar minerals that essentially have the same formula but vary in their percentage of sodium and calcium. Albite and Anorthite are the end members of the series, with the intermediary minerals Oligoclase, Andesine, Labradorite, and Bytownite.

Additionally, what is plagioclase feldspar made out of?

The plagioclase feldspar subgroup consists of a continuous mineral series that is arbitrarily subdivided into six mineral categories whose composition varies from being relatively pure sodium aluminum silicate (albite) to a relatively pure calcium aluminum silicate (anorthite).

What is the chemical composition of plagioclase?

Plagioclase Mineral Data

General Plagioclase Information
Chemical Formula: (Na,Ca)(Si,Al)4O8
Composition: Molecular Weight = 270.77 gm
Sodium 4.25 % Na 5.72 % Na2O
Calcium 7.40 % Ca 10.36 % CaO

39 Related Question Answers Found

What are the two main types of feldspar?

The feldspars are divided into two main groups: Potassium feldspar ("K-spar") and plagioclase ("plag").

How is feldspar formed?

Feldspars crystallize from magma in both intrusive and extrusive rocks, and they can also occur as compact minerals, as veins, and are also present in many types of metamorphic rock. Rock formed entirely of plagioclase feldspar is known as anorthosite.

Is feldspar flammable?

Feldspar is not flammable.

How many types of feldspar are there?

Feldspars are divided into two types:
  • K-feldspars (potassium feldspars)
  • Plagioclase feldspars (an isomorphous series between albite and anorthite)

Where feldspar is found?


Feldspar” is the name of a large group of rock-forming silicate minerals that make up over 50% of Earth's crust. [1] They are found in igneous, metamorphic, and sedimentary rocks in all parts of the world.

What color is quartz?

Pure quartz is white or colorless, but is commonly found in almost any color imaginable. Since quartz is naturally clear, any chemical impurities will allow the color to "shine" through. Amethyst, tiger eye, adventurine, and agates are all varieties of quartz with impurities in them to cause their distinctive color.

Who found feldspar?

Johan Gottschalk Wallerius

What is feldspar used for in everyday life?

Feldspar is a common raw material used in glassmaking, ceramics, and to some extent as a filler and extender in paint, plastics, and rubber. In glassmaking, alumina from feldspar improves product hardness, durability, and resistance to chemical corrosion.

Why is olivine green?

Olivine is named for its typically olive-green color, thought to be a result of traces of nickel, though it may alter to a reddish color from the oxidation of iron. The metamorphism of impure dolomite or other sedimentary rocks with high magnesium and low silica content also produces Mg-rich olivine, or forsterite.

What is feldspar worth?


The feldspar market is estimated to be USD 547.0 Million in 2017 and is projected to reach USD 745.7 Million by 2022, at a CAGR of 6.4%, in terms of value, between 2017 and 2022.

How do you identify amphibole?

Physical properties. Long prismatic, acicular, or fibrous crystal habit, Mohs hardness between 5 and 6, and two directions of cleavage intersecting at approximately 56° and 124° generally suffice to identify amphiboles in hand specimens. The specific gravity values of amphiboles range from about 2.9 to 3.6.

Is coal a mineral?

Coal is not classified as a mineral because it comes from organic materials. Coal is formed from the remains of dead plants and animals that are

How is hornblende formed?

Hornblende Minerals
Hornblende andesite: Hornblende is an important constituent in many igneous rocks. In extrusive rocks, hornblende sometimes crystallizes below the ground, in the magma, before eruption. That can produce large phenocrysts of hornblende in a fine-grained rock.

How is pyroxene formed?

The two mineral groups are related to one another, as during metamorphism water reacts with pyroxene minerals to convert them to amphibole. So pyroxenes are more common in rocks that formed in water-free settings, while amphiboles are more common in water-wet rocks or during late water-rich stages of magma cooling.

How do you identify feldspar?


In fact, feldspar is the standard for hardness 6 in the Mohs scale. Feldspars usually are white or nearly white, though they may be clear or light shades of orange or buff. They usually have a glassy luster. Feldspar is called a rock-forming mineral, very common, and usually makes up a large part of the rock.

Is ice a mineral?

Although many people do not think about Ice as a mineral, it is a mineral just as much as Quartz is. Ice is a naturally occurring compound with a defined chemical formula and crystal structure, thus making it a legitimate mineral. Snow crystals cling together to form snowflakes.

Is Obsidian a mineral?

Obsidian is mineral-like, but not a true mineral because as a glass it is not crystalline; in addition, its composition is too variable to be classified as a mineral. It is sometimes classified as a mineraloid.