Chlorite Group
Current inventory:  0 gems
 

  
Chlorite is named from the Greek word chloros meaning green, its typical color.  

Discovery year unknown; IMA status: Not Valid (not an individual mineral species; a group name)

Chemistry

Chemical Formula:

The general formula may be stated as:
A_5-6T₄Z₁₈, where A = Al, Fe²⁺, Fe³⁺, Li, Mg, Mn, or Ni, while T = Al, Fe³⁺, Si, or a combination of them, and Z = O and/or OH

Classification

Mineral Classification:

Silicates (Germanates)

Strunz 8th Ed. ID:

8/H.23-20

Nickel-Strunz 10th Ed. ID:

9.EC.55

9 : SILICATES (Germanates)
E : Phyllosilicates
C : Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets

Related to:

Chlorite Group.

Members of Group:

Chlorite Group: Baileychlore, Borocookeite, Chamosite, Clinochlore, Cookeite, Corundophilite, Donbassite, Franklinfurnaceite, Nimite, Orthochamosite, Pennantite, Sudoite 

Varieties:

Brunsvigite, Prasolite

Synonyms:

Chlorite, Oxychlorite, Viridite

Crystal Data

Crystallography:

Monoclinic - Prismatic

Occurances

Geological Setting:

Hydrothermal alteration product of amphibole, pyroxene and biotite.

View mineral photos:

Chlorite Mineral Photos and Locations

More Information

Mindat.org

The Chlorite Group of minerals is a group of mostly monoclinic micaceous phyllosilicate minerals that includes Amesite, Chamosite, Clinochlore (Kämmererite and Seraphinite) and Cookeite among others. The most common species in the Chlorite Group are Clinochlore and Chamosite. Chlorite is named from the Greek word chloros for green, referring to it’s typical color. Chlorite is not recognized by the IMA as an individual mineral species so the term Chlorite is often used to denote any member of the group when differentiation between the different members is not possible. There have been many names in past literature to describe Chlorites with small variations of chemical composition. The currently accepted names are: Chlinochlore (Mg-rich Chlorite), Chamosite (Fe-rich), Nimite (Ni-rich) and Pennantite (Mn-rich). Cookeite (with lithium substituted for aluminum) is also a member of the Chlorite Group. Chlorites characteristically occur as hydrothermal alteration products of other minerals such as Amphiboles, Pyroxenes and Biotites.

Chlorites are often known to gem collectors as green inclusions in Quartz and are particularly interesting when they form as a coating on a crystal early in its development. As the crystal later grows larger, ie. out and around the Chlorite coating, the effect produces a phantomed crystal. The interior "crystal" is often indistinct or ghostly and thus the name phantom.
 

Chlorite Group gems