| 11. | Riebeckite-granites have close affinities to aplites, shown especially in the prevalence of alkali feldspars.
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| 12. | Crystal twinning is common in feldspars, especially polysynthetic twins in plagioclase and Carlsbad twins in alkali feldspars.
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| 13. | As shown in the QAPF diagram, alkali feldspar granite contains between 20 %-60 % quartz.
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| 14. | Granite is classified according to the QAPF diagram for coarse grained petrologic convention contains both plagioclase and alkali feldspars.
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| 15. | In the case of the alkali feldspar minerals, thin white albite layers will alternate between typically pink microcline.
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| 16. | The alkali feldspar may have unusual compositions unlike any terrestrial feldspar, and they are often Ba-rich.
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| 17. | When a granitoid is devoid or nearly devoid of plagioclase, the rock is referred to as alkali feldspar granite.
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| 18. | "' Nepheline syenite "'is a holocrystalline plutonic rock that consists largely of nepheline and alkali feldspar.
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| 19. | They consist of quartz, plagioclase, orthoclase or alkali feldspar, rare mafics ( pyroxene ), and rare zircon.
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| 20. | Perthite is an intergrowth of alkali feldspar of intermediate composition : the coarseness of perthitic intergrowths is related to cooling rate.
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