feldspar

タイトルまたは説明

Feldspar group
potassium feldspar- Sodium feldspar-sodium potassium feldspar

General potassium feldspar

Orthoclase (endmember formula KAlSi3O8) is an important tectosilicate mineral which forms igneous rock
It is the most abundant minerals about *0 % of the distribution minerals in the earth crust in rocks from acidic to ultra basic rocks , occur as pegmatite veins ,cutting through the basement intrusive and volcanic rocks. the most important one is pegmatite .
Feldspar minerals are sodium, potassium, and calcium aluminosilicates. Their ores are commonly associated with quartz and mica, kaolin, garnet, or iron minerals depending upon the type of deposit . also there is wadi feldspar
The exploration by open cast way and the ore collected manually .
Orthoclase is a common constituent of most granites and other felsic igneous rocks and often forms huge crystals and masses in pegmatite.
Typically, the pure potassium endmember of orthoclase forms a solid solution with albite, the sodium endmember (NaAlSi3O8), of plagioclase. While slowly cooling within the earth, sodium-rich albite lamellae form by exsolution, enriching the remaining orthoclase with potassium. The resulting intergrowth of the two feldspars is called perthite. also there is wadi feldspar
General Sodium feldspar

It is one of  the most abundant minerals in the earth crust in rocks from acidic to ultra basic rocks , occur as pegmatite veins ,cutting through the basement intrusive and volcanic rocks. the most important one is pegmatite .
Feldspar minerals are sodium, potassium, and calcium aluminosilicates. Their ores are commonly associated with quartz and mica, kaolin, garnet, or iron minerals depending upon the type of deposit .
The exploration by open cast way and the ore collected manually .

General potassium feldspar
Category Silicate mineral

Chemical formula
KAlSi3O8
Identification
Color Colorless, Greenish, Grayish yellow, White, Pink
Crystal habit
anhedral or euhedral.

Crystal system
Monoclinic

Twinning
Typically displays carlsbad twinning.
Cleavage
Has perfect cleavage on {**1} and good cleavage on {**0}. Cleavages intersect at *0°.
Mohs scale hardness 6
Luster
Vitreous, pearly on cleavage surfaces
Streak
white
Diaphaneity
Transparent to translucent
Specific gravity
2.*5–2.*3
 
 
 
Dispersion
relatively strong
Extinction parallel to cleavage
 
 

General Sodium feldspar
Category plagioclase, feldspar,

Chemical formula
NaAlSi3O8
Crystal symmetry
Triclinic
 
Identification
Color White to gray, bluish, greenish, reddish; may be chatoyant

Crystal habit
tabular, divergent aggregates, granular, cleavable massive
Crystal system
Triclinic

Twinning
polysynthetic striae on {**1} or {**0}also contact, simple and multiple
Cleavage
Perfect on {**1}, very good on {**0}, imperfect on {**0}
Fracture
Uneven to conchoidal
Tenacity Brittle
Mohs scale hardness 6 – 6.5
Luster
Vitreous, typically pearly on cleavages
Streak
White
Diaphaneity
Transparent to translucent
Specific gravity
2.*0 - 2.*5
 
 
 
 
 
Other characteristics Low- and high-temperature structural modifications are recognized