The Mineral clinochlore

Clinochlore is a member of the Chlorite group and is one of the better-known members. It most often is an uninteresting matrix for more important minerals, but the rare and beautiful pink to red variety Kammererite is very popular and treasured by collectors.

Clinochlore forms a series with the Chamosite within the Chlorite group. Chamosite is the iron rich end member, and Clinochlore is the magnesium-rich end member. Their properties are very similar, and they are difficult to distinguish from each other, though Clinochlore is softer, lighter, and usually more transparent than Chamosite.

Chemical Formula

(Mg,Fe²⁺)₅Al₂Si₃O₁₀(OH)₈

Color

Light to dark green, pink, red, purple, yellow, gray, brown, white, black

Crystal System

Monoclinic

Properties

Streak White

Hardness 2 - 2.5

Transparency Transparent to translucent

Specific Gravity 2.55 - 3.0

Luster Vitreous to pearly

Cleavage 1,1

Fracture Uneven

Tenacity Thin flakes are flexible but not elastic.

Other ID Marks May have a slightly greasy feel.

Crystal Habits

Crystals are usually tabular and pseudohexagonal in shape, but also may be prismatic. Also as thick flakes, micaceous masses and groupings, and in foliated, flaky, and scaly forms. May also be massive, radiating, and globular masses of dense flakes.

Clinoclore may form pseudomorphs and dense coatings of other minerals, assuming the original minerals crystal shape.

3D Crystal Atlas

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Additional Information

Composition Basic iron magnesium aluminum silicate. May also contain small amounts of chromium.

In Group Silicates; Phyllosilicates; Chlorite Group

Striking Features Color and lack of elasticity

Environment Always an alteration mineral. Commonly in metamorphic environments, especially in Serpentine deposits; also as a secondary mineral in hydrothermal replacement deposits.

Rock Type Metamorphic

Other Names

Ripidolite

Varieties

Kammererite

 -   Chromium-rich variety of Clinochlore with a pink to deep crimson-red color. Also spelled Kämmererite or Kaemmererite.

Pennine

 -   Clinochlore with pseudohexagonal crystals.

Seraphinite

 -   Trade name for Clinochlore polished with feathery-like chatoyancy. Used as a minor gemstone.

Uses

The pink to purple chromium-rich variety of Kammererite is a rare and popular collectors mineral.

Noteworthy Localities

Noteworthy locations include the Korshunovskoye mine, Zheleznogorsk, Russia; the Fee Glacier in the Saas Valley, Wallis, Switzerland; the Zillertal, Tyrol, Austria; and Val Malenco, Sondrio, Italy.

The most famous locality for Kammererite is the Kop Krom mine, Kop Daglari, Erzurum, Turkey; where it comes in transparent gemmy crystals of deep and beautiful crimson color. Kaemmererite also comes from Turkey at Guleman, Elazig.

In the U.S., the original type locality is Brinton's Quarry, West Chester, Chester County, Pennsylvania. Other localities are the Old Mine Plaza, Trumbull, Fairfield Co., Connecticut; the New Idria District in the Diablo Range, San Benito Co., California; and the Jeffrey mine, Asbestos, Quebec, Canada.

Exceptional Clinochlore crystals came from the old Tilly Foster mine, Brewster, Putnam Co., New York, sometimes in strange pseudomorphs after other minerals. Excellent pseudomorphs of Chlorite after Garnet come from Michigamme, Marquette Co., Michigan. A classic Kammererite locality in the U.S. is the Wood's Chrome Mine, Texas, Lancaster Co., Pennsylvania.

Common Mineral Associations

Calcite, Albite, Orthoclase, Grossular, Diopside, Serpentine, Talc, Quartz, Magnetite, Almandine

Distingushing Similar Minerals

Muscovite and other micas - Are more elastic then Chlorites.
Talc - Softer (1).
Other Chlorite minerals - Indistinguishable by practical methods.

clinochlore Photos

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