Mafic minerals are usually dark in color and have specific gravities greater than 3. Common rock-forming mafic minerals include olivine, pyroxene, amphibole, biotite and other micas, augite[?] and the plagioclase feldspars. Common mafic rocks include basalt and gabbro.
In terms of chemistry, mafic rocks are on the other side of the rock spectrum from the so-called felsic rocks.
Rock Texture | Name of Mafic Rock |
Pegmatitic | Gabbro pegmatite |
Coarse grained (phaneritic[?]) | Gabbro |
Coarse grained and porphyritic[?] | Porphyritic gabbro |
Fine grained (aphanitic[?]) | Basalt |
Fine grained and porphyritic | Porphyritic basalt |
Pyroclastic[?] | Basalt tuff or breccia |
Vesicular[?] | Vesicular basalt |
Amygdaloidal[?] | Amygdaloidal basalt |
Many small vesicles[?] | Scoria[?] |
Glassy[?] | Tachylyte[?] or palagonite[?] |
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