Cochise College Photos of Minerals

Roger Weller, geology instructor

[email protected]
copyright 2006-R.Weller

Mineral Information on:
mimetite

Chemical Group:    arsenate

Chemical Formula:    Pb₅Cl(AsO₄)₃

Color:  pale yellow, brown, orange yellow, white, colorless

Streak: white or close to it           Fracture: uneven

Hardness: 3.5 Specific Gravity: 7.0 to 7.25

Tenacity: brittle Cleavage: imperfect

Crystal Forms: Hexagonal-tripyramidal
   Commonly rounded to globular; mammillary crusts
     Rounded, barrel-like crystals (campylite)

Mineral Associations:
     It is found in lead deposits that have undergone secondary alteration
     Often found with limonite and carbonates.
     Commonly occurs with wulfenite.

Identifying Characteristics: yellow to orange globular clusters; high density

Uses: lead ore

Occurrences:
USA
Arizona:
     Red Cloud Mine, Yuma County
     79 mine, Gila County
     Mammoth-St. Anthony mine, Pinal County
Pennsylvania:
     Wheatley and Charleston mines, Phoenixville
Utah:
     Tintic district, Eureka
World-Wide
Algeria:
     Sidi Rouman, Bou-thaleb, and Djebel Grous
Australia:
     Broken Hill area, New South Wales
     Mt. Bonney mine, Price's Spring Station, Grove Hill, Northern Territory
     Tasmania
England:
     Roughten Gill, Caldbeck Fells, Cumberland
     Wheal Alfred, Cornwall region
France:
     Pontigibaud district, Puy-de-Dome
     Les Farges mine

Germany:
Johanngeorgenstadt, near Erzgebirge
Mexico:

     Santa Eulalia, Chihuahua
     El Leon mine, San Pedro Mining District, Corralitos, Chihuahua
     Bilboa mine, Zacatecas
     San Francisco Mine, Cerro Prieta, Magdalena, Sonora
     Ojuela Mine, Mapimi
     Santa Eulalia
Southwest Africa
     Tsumeb

Toxicity:      when-swallowed- very high       when inhaled- very high

Additional Information: