What is the crystal structure of feldspar?
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geology
Crystal structure. Sanidine and orthoclase are monoclinic or nearly so; the plagioclase feldspars are triclinic.
Besides, what is the structure of feldspar?
The structure of feldspars is a three-dimensional framework of linked SiO4 and AlO4 tetrahedra, with sufficient opening in the framework to accommodate K, Na, Ca, or Ba to maintain electroneutrality. In the building up of the framework, four-membered rings of tetrahedra are the basic units.
Just so, is feldspar a crystal?
The potassium feldspar group is composed of three mineral polymorphs, each having the same chemical composition, but slightly different crystal structures. All of the feldspar minerals exhibit a blocky crystal habit, hardness greater than glass, and two directions of cleavage that meet at nearly right angles.
Generalized Physical Properties of Feldspar Minerals | |
---|---|
Chemical Classification | Silicate |
Diaphaneity | Usually translucent to opaque. Rarely transparent. |
Cleavage | Perfect in two directions. Cleavage planes usually intersect at or close to a 90 degree angle. |
Mohs Hardness | 6 to 6.5 |