Hornblende Photos   
Cochise College               
Photos of Minerals
Virtual Geology Museum      Hall of Minerals

Geology Home Page

Roger Weller, geology instructor

wellerr@cochise.edu     copyright 2008-R.Weller 

 
hornblende cleavage-1
As an exciting, colorful mineral, hornblende doesn't make the list.
Hornblende is the most common member of the amphibole family of silicate
minerals.  Besides silica, it has a little bit of everything else in its chemistry: ferrous
and ferric iron, aluminum, calcium, manganese, magnesium, and alkalis.
Hornblende forms prismatic, dark brown to black, small crystals in many igneous
rocks.  It is most commonly confused with the mineral augite that forms shorter,
stubby crystals.  Hornblende can be distinguished from augite by its cleavage; the
two cleavage planes in augite are nearly at right angles, while the two cleavage
planes in hornblende are at an angle of 124 degrees.
 

hornblende
Photo is copyright free for non-commercial educational uses.
Just credit photo to R.Weller/Cochise College.