DEGREE OF CRYSTALLINITY Flashcards

1
Q

holohyaline

A

rock composed entirely of glass; no crystals visible even with magnification

indicates cooling so rapid no crystal growth could occur

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2
Q

holocrystalline

A

rock composed entirely of crystals(which may or may not be visible without
magnification)

indicates cooling sufficiently slow to allow complete crystallisation to occur

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3
Q

hypocrystalline

A

rock composed both crystals/glass

indicate period or relatively slow cooling follwed by quenching f remaining magma

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