The chlorites are often, but not always considered a subset of the larger silicate group, The clays . However there are several different minerals that are apart of the chlorite group of minerals. The above formula is only a generalization of the more common members of this group. In order to see a list of most of the chlorite group minerals with their respective formula, see the discussion of the Chlorite Group . For practical reasons most of the chlorites will be considered here as a single mineral, chlorite.
Chlorites are generally green and crystallize in the monoclinic symmetry system.
They all have a basal cleavage due to their stacked structure. Chlorites typically form flaky microscopic crystals and it is this reason that they are sometimes included in the clay group of minerals. However chlorites also form large individual tabular to platy crystals that are unlike most of the other clay minerals. Chlorites are most often known to mineral collectors as inclusions in or coatings on quartz , danburite , topaz , calcite and many other minerals. The inclusions are usually a very strong green color despite the small amount of material that actually constitutes the inclusion.