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2 at 90 degrees
Here is a discussion on feldspar.
It says it has uneven fracture and cleavage in 2 directions.
http://www.theimage.com/mineral/feldspar/index.htm
What else can I help you with?
Why do some silicate minerals have cleavage and others do not?
Silicate minerals exhibit cleavage based on their crystal structure and the bonding between silicon-oxygen tetrahedra. Those with a more organized arrangement of tetrahedra, such as micas and feldspars, tend to have well-defined cleavage planes due to weaker bonds along specific directions. In contrast, silicates with a more complex structure or stronger bonds in multiple directions, like quartz, typically do not exhibit cleavage and instead fracture irregularly. Thus, the arrangement of tetrahedra and the nature of the chemical bonds dictate the presence or absence of cleavage in silicate minerals.
The first feldspars to form are rich in what element?
calcium
The way a mineral splits is called?
CLEAVAGE
Does a mineral have crystal form but no cleavage?
All minerals have a crystal form, but not all have cleavage.
Which rocks are used in glass and ceramic industries?
Kaolinite and some feldspars.
What physical properties distinguish plagioclase feldspars from orthoclase feldspars?
One physical property that distinguishes plagioclase feldspars from orthoclase feldspars is their cleavage. Plagioclase feldspars typically exhibit good cleavage in two directions at right angles, while orthoclase feldspars show perfect cleavage in one direction. Another distinguishing feature is their color. Plagioclase feldspars are usually white to gray, while orthoclase feldspars can be white, pink, or other colors.
Tendency to break along smooth flat surfaces?
Many minerals have "cleavage" that causes them to split on flat cleavage planes. Such minerals include micas (muscovite, biotite. phlogopite), calcite, gypsum, and feldspars. Cleavage is the result of the minerals' crystal structure that has weaker chemical bonds aligned in planes.
What physical properties distinguish plagioclase feldspars from othoclase feldspars?
Plagioclase feldspars have a higher calcium content compared to orthoclase feldspars, as well as a different crystal structure. In terms of appearance, plagioclase feldspars often exhibit striations and twinning, which are less common in orthoclase feldspars.
Do Orthoclase and plagioclase feldspars have quite different forms of cleavage?
Orthoclase feldspar typically exhibits two cleavage planes at right angles to each other, forming blocky or prismatic shapes. Plagioclase feldspar, on the other hand, shows two cleavages at nearly 90 degrees but often also has a third cleavage at a slightly different angle, resulting in more varied forms.
How does the cleavage of feldspar differ from the cleavage of mica?
Biotite (black mica) and muscovite (white mica) are both minerals that have perfect basal cleavage--one direction. It cleaves into thin sheets. Feldspars (albite, oligoclase, andesine, labradorite, bytownite, anorthite) have good cleavage in two directions at nearly right angles, poor in a third direction.
What is feldspars' hardeness?
Feldspars generally have a hardness of 6 on Mohs' hardness scale.
What are the 2 most common silicate minerals in Earth's crust?
feldspars. feldspars.
What is the feldspars streak?
White
Are feldspars and hematite examples of native elements?
No, feldspars and hematite are not examples of native elements. Native elements are minerals that are composed of a single element in its pure form, such as gold or silver. Feldspars are a group of minerals containing aluminum, silicon, and oxygen, while hematite is an iron oxide mineral.
What is sulfurs cleavage cleavage?
Sulfur's cleavage is imperfect.
How does iron - magnesium and feldspars crystallize from magma?
Feldspars are the first to crystallize at the eutectic point after which the temperature drops, thus crystallizing the iron - magnesium.
What are the two most common silicate minerals in earths crust?
Quartz and feldspars are the most common silicate minerals of the crust.
