Asked by: Valdas Christians
Asked in category: science, geology
Last Updated: 29th Apr 2024
How is plagioclase feldspar different from orthoclase feldspar?
The plagioclase is different from the orthoclase because it contains additional metals. Plagioclase has calcium and sodium, while orthoclase has potassium. The feldspars are similar in physical properties, and have a luster that can range from pearly to glassy.
You may also wonder, "What is the major difference between orthoclase and plagioclase?feldspar?"
Plagioclase-feldspars are low in potassium, have light colors and are often striated. Anorthoclase, microcline, and sanidine are the other k-spar mineral k-spars. Orthoclase, which is the most common of all k-spars, is the most prevalent. Hand samples show that there are very few differences between the minerals.
You might also wonder what the most common element is in orthoclase and plagioclase. These 3 elements are what determine the specific form of feldspar. Plagioclase is composed of calcium and sodium, and orthoclase contains potassium.
It is also important to understand if plagioclase is feldspar.
Plagioclase, a member the feldspar group (like Orthoclase), is a framework-silicate. Plagioclase is a solution of anorthite and albite end-members. It is one of the most popular rock-forming minerals.
What are the differences between feldspar and feldspar?
The feldspars can be divided into two groups: Plagioclase ("plag") and Potassium Feldspar ("Kspar").
17 Related Question Answers Found
What are the types of feldspar?
The alkali feldspars include orthoclase, microcline, sanidine, anorthoclase, and the two-phase intermixtures called perthite. The plagioclase feldspars include members of the albite-anorthite solid-solution series.
What type of rock is pink feldspar?
Orthoclase is a feldspar mineral with a chemical composition of KAlSi3O8. It is one of the most abundant rock-forming minerals of the continental crust. Orthoclase is most widely known as the pink feldspar found in many granites and as the mineral assigned a hardness of "6" in the Mohs hardness scale.
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.
What color is Feldspar?
In general, potassium feldspars commonly have pink to reddish hues, while the plagioclase feldspars tend to be white or gray, but both mineral groups may exhibit similar colors, so the presence or absence of striations is more diagnostic.
What is feldspar made of?
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.
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.
How do you identify a feldspar in a thin section?
Hardness (6-6.5) and cleavage are good indicators of a plagioclase as opposed to other similar silicates. In thin section or grain mount, the general lack of pleochroism and the twinning are good indicators. The presense of parallel striae on cleavage surfaces distinguishes plagioclase from K-feldspar.
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
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.
Does feldspar react to acid?
Minerals - Reaction to Hydrochloric Acid. Carbonate minerals such as calcite tend to fizz or efferves when tested with Hydrochloric Acid (HCl). Non-carbonate minerals, especially silicates will not react to HCl.
Why is K feldspar pink?
K–feldspar albite intergrowths known as pertite and albite intergrowths K–feldspar as antipertite. The hardness is from 6 to 6.5 and the relative density of 2.55–2.63. The color is usually white, and sometimes changes from pale pink to reddish due to admixtures of iron (especially microcline).
Which feldspar has exsolution lamellae?
Perthite is used to describe an intergrowth of two feldspars: a host grain of potassium-rich alkali feldspar (near K-feldspar, KAlSi3O8, in composition) includes exsolved lamellae or irregular intergrowths of sodic alkali feldspar (near albite, NaAlSi3O8, in composition).
How do you identify hornblende?
Identification of Hornblende
Hornblende minerals as a group are relatively easy to identify. The diagnostic properties are their dark color (usually black) and two directions of excellent cleavage that intersect at 124 and 56 degrees.What is pyroxene used for?
In Our Society: The Economic Importance of Pyroxene
Spodumene is mined as an important source of lithium, used in ceramics, and is also prized as a gemstone. Jadeite is one of two minerals commonly known as jade (nephrite, an amphibole mineral, is the other jade variety).What does plagioclase feldspar look like?
Plagioclase Series of the Feldspar Group of Silicate Minerals. Typically white to gray, may also range from colorless, through shades of off-white, to yellowish, pink, reddish brown or nearly black. Common twinning in the crystal structure that creates fine parallel grooves or striations on some cleavage surfaces.
What is black mica?
Biotite is a name used for a large group of black mica minerals that are commonly found in igneous and metamorphic rocks. These micas vary in chemical composition but are all sheet silicate minerals with very similar physical properties.
Similar Asks
Trending Questions
Co-authors
4
Updated On
29th Apr 2024
Views
774
18
Questions
44
Answers
1
Videos
8
Users
95% of readers found this page helpful.
4.3/5
Rate this post by clicking on a star above
Thank you for your vote!