Rocks 2 Flashcards
importance of rocks
evidence of past, principle of uniformitarism
other uses of looking at rocks
hazard analysis, glacial/river reconstruction, environmental analysis
rock
naturally occurring mass of organic/inorganic material
mineral
naturally occurring inorganic solid with chemical composition
mineral identification
crystal habit (symmetry), cleavage, hardness, colour, lustre, magnetism, optical properties
hard minerals
covalent
less hard minerals
ionic
soft minerals
van der waals
what do some minerals have
an element changes meaning change to whole mineral
crystal system
defines length of sides/angles
crystal growth
needs ions/atoms, space, temp, pressure
crystal destruction
melting/dissolution/chemical alteration
native element
one element
mineral classes
sulfates, halides, oxides etc
main mineral on earth
silicate
intrusive/plutonic
inside earth, slow cooling, coarse
extrusive
fine, minerals have no time to grow
hight melting temp
mafic
low melting temp
felsic
partial melting
subduction zones brings water and lowers melting point)
fractional crystallisation
removal of minerals changes composition (mafic to silica)
assimiliation
magma erupts and melts rock
magma mixing
partial melting magma mixes with magma chamber
felsic magma
quartz/muscovite
