Petrology Definitions Flashcards
Phaneric texture
A texture that can be observed optically
Crystalline
A rock which consist of crystals that fit against another one another to form a mosaic
Aphanatic texture
A textu that cannot be observed without any artificial means
Porphyritic texture
When large crystals a contained in a fine grained groundmass
Define Metamorphism
A redistribution of atoms in the mineral that form new minerals which are stable at changed conditions
Foliation
When minerals re-orientate themselves perpendicular to the direction of the maximum pressure
Crystalline foliation
When minerals which are foliated alternate with bands of other minerals
Crsytalloblastic
when a metamorphic rock has the same texture as igneous
Crystallotopic
When sedimentary rocks displays same texture as igneous rocks
Define Magma
A silicate melt which contains appreciable amounts of water vapor and volatile constituents
Holocrystalline
When a rock consist of crystals only
Hypocrystalline
When a rock consist of volcanic glass and crystals
Cryptocrystalline
When a rock consist of only volcanic glass
Pegmatite
A rock consisting of only coarse grained crystals
Aplitic
A rock that consist of only fine grained crystals
