Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                          [email protected]
                                  copyright 2010-R.Weller

Mineral Information on:
neptunite

Chemical Group:  silicate

Chemical Formula:   (Na,K)₂(Fe,Mn)(Si,Ti)₅O₁₂

Color:   black to reddish black                                                                      

Streak:  cinnamon brown

Hardness:    5 to 6             Specific Gravity:   3.23 

Luster:  vitreous     
 

Tenacity:  brittle         

Fracture:  conchoidal

Cleavage: 1 direction

Crystal Forms:  Monoclinic system, prismatic crystals

Mineral Associations:  benitoite and natrolite

Identifying Characteristics:

Uses:

Occurrences:  San Benito County, California

Toxicity:      when-swallowed-                            when inhaled-

Additional Information: