From Conservapedia
The
amphiboles are a family of
silicate minerals that form prism or needle-like
crystals. Amphibole minerals generally contain
iron,
magnesium,
calcium and
aluminum in varying amounts along with
silicon,
oxygen, and
water.
Hornblende, shown in this image, is a common dark green to black variety of amphibole; it is a component in many
igneous and
metamorphic rocks.
[1]
References
- ↑ http://wrgis.wr.usgs.gov/docs/parks/rxmin/mineral.html#amphibole
