Astrophyllite

saf-ahyuh r

Astrophyllite is golden-yellow to dark brown and usually forms as bladed crystals radiating from a common center. It gets its name from the Greek astron, meaning "star", and phyllon, meaning "leaf." It may also be translated as "star sheets," fitting because of the interwoven star shapes that the crystals sometimes form and because of its strange luster, which can be metallic in some crystals and pearly in others. Although there are occurrences of astrophyllite around the world, some of the finest crystals come from remote mountainous regions in arctic northern Russia.

Astrophyllite Polished
Astrophyllite Classification
Common Name Astrophyllite
Species Astrophyllite
Astrophyllite Optical Properties
Transparency Translucent - Opaque
Dispersion Strength: Strong Fire
Refractive Index 1.678-1.758
Optic Character Biaxial
Optic Sign Positive
Polariscope Reaction Aggregate (AGG), Doubly Refractive (DR)
Pleochroism Trichroic, orangy red, orangy yellow, yellow
Astrophyllite Characteristic Physical Properties
Hardness 3
Streak Golden
Specific Gravity 3.200-3.400
Toughness Poor
Inclusions The stone is composed of star or leaf like sheets some of which can have a metallic or pearly luster.
Luster Greasy, Pearly
Fracture Uneven
Cleavage Perfect, in one direction, Poor, in one direction
Astrophyllite Chemistry & Crystallography
Chemical Name potassium sodium iron manganese titanium silicate hydroxide
Chemical Formula (K,Na)3(Fe2+,Mn)7Ti2Si8O24(O,OH)7
Crystal System Triclinic
Chemistry Classification Silicate

Astrophyllite Colors

  • Brown Astrophyllite Brown

Countries of Origin

Russian Federation (the)

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Tim Matthews

Tim Matthews is President and Chief Executive Officer of Jewelry Television® (JTV), as well as a member of the company's Board of Directors. He oversees and leads all aspects of the company's powerful omni-digital retail platform that uniquely specializes in fine jewelry and gemstones. His passion for business and gemstones has led him to become a recognized expert in the field of gemology. He is a life member of the Gemmological Association of Great Britain (Gem-A) and has earned Gem-A's highest degrees, the Gemmology (FGA) and Diamond (DGA) diplomas. He is also a Graduate Gemologist (GG) of the Gemological Institute of America (GIA) and has also completed GIA's Graduate Diplomas in Diamonds, Colored Stones and Pearls. Under his leadership, JTV has become the leader in the sourcing and selling of color gemstones and jewelry.

This page was created on June 27, 2014.

This page was last edited on October 24, 2019.