Geology ed

free textbook at https://opengeology.org/textbook/

Minerals ed

silicate

• felsic: high Si, low density, lower melting temp, brighter, closer to the surface
• intermediate
• mafic: lower Si, more Mg, Fe,.... mantle
• ultramafic:

igneous

• extrusive: quickly to the surface, fine grained
• intrusive/plutonic: cooling slowly below surface, coarse grained

texture

• aphanitic: very fine grained, glass like
• pegmatitic: very large grains, slow
• porphyritic: fine grained with large chunks, multistage cooling
• vesicular: bubbles from dissolved volatiles

examples

• olivine: (Fe,Mg)_2 Si O_4, making most of the mantle, ultramafic
• basalt
• granite:
• obsidian:

Volcanoes ed