Encyclopedia > Felsic

  Article Content


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 TextureName of Felsic Rock
Pegmatitic[?]Granite pegmatite
Coarse grained (phaneritic[?])Granite
Coarse grained and porphyritic[?]Porphyritic granite
Fine grained (aphanitic[?])Rhyolite
Fine grained and porphyriticPorphyritic rhyolite
Pyroclastic[?]Rhyolitic tuff or breccia
Many small vesicles[?]Pumice

See also: List of minerals

All Wikipedia text is available under the terms of the GNU Free Documentation License

  Search Encyclopedia

Search over one million articles, find something about almost anything!
  Featured Article
Heathrow airport

... and the United States is strictly governed by the countries' bilateral Bermuda II[?] treaty. The treaty originally allowed only British Airways, Pan American and TWA to ...