Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                          wellerr@cochise.edu
                                  copyright 2005-R.Weller
 

Mineral Information on:
calcite

Chemical Group:    carbonate

Chemical Formula:   
CaCo3

Color:  colorless, white, gray, red, green, blue, violet, yellow,
     brown, black

Luster:  vitreous to sub-vitreous to earthy   
                                                                        
Streak:  white to grayish           Transparency:  transparent to opaque

 

Hardness:   3                 Specific Gravity:  2.710                 

Cleavage:  rhombohedral, 3 directions

 

Crystal Forms and Habits:  Trigonal system
   Calcite crystallizes in a wide variety of modified rhombohedrons and scalenohedrons.
   Calcite occurs in many forms: massive,  stalactitic, fibrous, earthy, layered, etc.
 
Mineral Associations:

Identifying Characteristics:  Reacts strongly with dilute hydrochloric acid: bubbles of CO2 are released.
     A clear variety of calcite (Iceland Spar) displays double refraction.

Uses:

Occurrences:  All over the world, but crystals are more commonly in vugs in limestones. 

Toxicity:      when-swallowed- low        when inhaled- low

Additional Information: