Felsic is a term used in geology to refer to silicate minerals, magmas, and rocks which are enriched in the lighter elements, such as silica and oxygen, aluminum, and potassium. The term combines the words "feldspar" and "silica."
Felsic minerals are usually light in color and have specific gravities less than 3. Common felsic minerals include quartz, biotite, muscovite mica, hornblende and the orthoclase feldspars. The most common felsic rock is granite.
On the opposite side of rock spectrum are "mafic" rocks.
Rock Texture | Name of Felsic Rock |
Pegmatitic | Granite pegmatite |
Coarse grained (phaneritic) | Granite |
Coarse grained and porphyritic | Porphyritic granite |
Fine grained (aphanitic) | Rhyolite |
Fine grained and porphyritic | Porphyritic rhyolite |
Pyroclastic | Rhyolitic tuff or breccia |
Vesicular | None |
Amygdaloidal | None |
Many small vesicles | Pumice |
Glassy | Obsidian |
See also: List of minerals