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Golden Brown Pyrophyllite

The Mineral pyrophyllite

Pyrophyllite is isomorphous with the common mineral Talc, but has aluminum in place of the magnesium. It is very similar to Talc, with very similar properties and habits. However, it has distinct radiating crystal aggregates which easily identify it. Pyrophyllite is named after the Greek words "pyr" - "fire" and "phyllon" - leaf, regarding its property to exfoliate into fan shapes upon heating.
Chemical Formula Al2Si4O10(OH)2
Composition Basic aluminum silicate
Color White, light green, apple-green, gray, yellow, brown, light blue
Streak White
Hardness 1 - 2
Crystal System Monoclinic
Crystal Forms
and Aggregates
In dense masses of radiating crystals, often in the shape of interconnected fans. Also in compact veins, and in  radial balls and rosettes. Usually in massive, compact form, with distinct radiating crystals visible.
Transparency Translucent to opaque
Specific Gravity 2.8 - 2.9
Luster Pearly, dull
Cleavage 1,1
Fracture Splintery, uneven
Tenacity Flexible but inelastic
Other ID Marks 1) Has a greasy feel.
2) May fluoresce yellow in longwave ultraviolet light.
In Group Silicates; Phyllosilicates
Striking Features Distinct crystal habits, light weight, and greasy feel.
Environment In metamorphic schists and hydrothermal replacement deposits.
Rock Type Metamorphic
Popularity (1-4) 3
Prevalence (1-3) 2
Demand (1-3) 2

Pyrophyllite AUCTIONS

 -  Chromium-rich, deep green variety of Pyrophyllite.

Pyrophyllite is used for ceramics, in paints, insecticides, and in the production of rubber. It is also used as a minor ornamental stone for carvings and sculptures.

Localities where good Pyrophyllite specimens have come from are limited. Radiating yellow sprays come from Gundagai, New South Wales, Australia; and Monte Folgorito, Pietrasanta, Tuscany, Italy. Light green Pyrophyllite was found in St Niklaus, Zermatt-Saas Fee area, Valais, Switzerland.

In the U.S., North Carolina has produced some of the finest collectible examples of this mineral. Localities include Staley, Randolph Co.; Hillsboro, Orange Co.; the Snow Camp Mine, Alamance Co.; and Cotton Stone Mountain, Troy, Montgomery Co. Dense sprays of large Pyrophyllite crystals have come from Graves Mountain, Lincoln Co., Georgia; and golden-brown interconnected radial sprays associated with Rutile from the Champion Mine, White Mountains, Inyo Co., California.

Quartz, Chlorite, Hematite, Muscovite, Albite, Rutile, Kyanite, Andalusite, Lazulite

Talc - Slightly softer, lacks distinct crystal habits of Pyrophyllite. Massive Talc and Pyrophyllite can be very difficult to distinguish.
Wavellite - Greater hardness, different mode of occurrence.

pyrophyllite PHOTOS
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