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What is a sodium an calcium feldspar with twinning striations called?
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∙ 14y ago
Plagioclase.
Wiki User
∙ 14y ago
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What is the most calcium-rich variety of plagioclase feldspar called?
Anorthite
What element makes up feldspar?
It depends on the type of feldspar. Potassium Feldspar (also called K-Spar), contains potassium, aluminum, silicate: KAlSi3O8. Plagioclase Feldspar, on the other hand, contains calcium or sodium, aluminum, and silicate: NaAlSi3O8 or CaAl2Si2O8.
What are the scratch marks on rocks from moving glaciers called?
striations, striae
How does arkose form?
Arkose is formed from the weathering of feldspar-rich igneous metamorphic granitic rocks. They are usually composed of quartz and feldspar called 'grus'.
What is microline feldspar?
Alkali feldspar has the general formula (K,Na)AlSi3O8, but varies in crystal structure depending on the temperature it formed at. The formula actually is a blend ranging from all sodium (albite) to all potassium (microcline), but albite is also one endpoint in the plagioclase series so we classify albite there. This mineral is often called potassium feldspar or K-feldspar, because by definition potassium always exceeds sodium in its formula. It comes in three different crystal structures that depend on the temperature it formed at. Microcline is the stable form below about 400° C. Orthoclase is stable above 500° C and sanidine is stable above 900° C. In a plutonic rock that cooled very slowly to yield large mineral grains, it's safe to assume that this is microcline. In the field, workers generally just write down "K-spar" and leave it at that until they can get to the laboratory. Alkali feldspar is generally white, buff or reddish and is not transparent, nor does it show the striations of plagioclase. A green feldspar is always microcline, the variety called amazonite.
What is the most calcium-rich variety of plagioclase feldspar called?
Anorthite
What are the scratches left behind from glaciers called?
striations
What element makes up feldspar?
It depends on the type of feldspar. Potassium Feldspar (also called K-Spar), contains potassium, aluminum, silicate: KAlSi3O8. Plagioclase Feldspar, on the other hand, contains calcium or sodium, aluminum, and silicate: NaAlSi3O8 or CaAl2Si2O8.
What is a Long scratch marks that are left behind as evidence of glaciers are called?
They are called striations.
Which type of muscle doesn't have stripes?
The "stripes" in the muscle are called striations. Smooth muscle doesn't have the striations.
What are very large striations called?
Glacial Cracks
What are striations how are they formed?
As glaciers move over Earth's surface, the ice acts like sandpaper. The scratch marks that are visible when the ice melts are called striations.
What are the parallel lines seen on crystal faces or cleavage planes?
These are called striations.
What are the scratch marks on rocks from moving glaciers called?
striations, striae
What is the line or streak across a muscle called?
Microscopically you could be seeing sacromeres. Otherwise, these streaks are called striations.
Muscle type with striations but not under voluntary control is called?
skeletalMuscle
How does arkose form?
Arkose is formed from the weathering of feldspar-rich igneous metamorphic granitic rocks. They are usually composed of quartz and feldspar called 'grus'.
