Apophyllite

saf-ahyuh r

Apophyllite is divided into three distinct species, fluorapophyllite, hydroxyapophyllite and natroapophyllite, depending on their chemical composition. It was once considered to be a single mineral, so if chemical composition is not yet determined specimens will still be referred to as apophyllite. It is commonly found as glassy prismatic, blocky, or tabular white to grayish or light pastel crystals. The name apophyllite comes from the Greek word meaning "leafs off," referring to its tendency to flake when heated.

Apophyllite Polished
Apophyllite Classification
Common Name Apophyllite
Species Apophyllite
Apophyllite Optical Properties
Transparency Transparent - Translucent
Dispersion Strength: Strong Fire
Refractive Index 1.535-1.537
Birefringence 0-0.002
Optic Character Uniaxial
Optic Sign Positive or Negative
Polariscope Reaction Doubly Refractive (DR)
Fluorescence SWUV: inert to moderate yellowish white or green
LWUV: Inert to moderate yellow or yellowish white
Pleochroism None
Apophyllite Characteristic Physical Properties
Hardness 4.5-5
Streak White
Specific Gravity 2.300-2.500
Toughness Poor
Luster Vitreous, Pearly
Stability Poor
Fracture Uneven
Cleavage Perfect, in one direction, good in one direction
Apophyllite Chemistry & Crystallography
Chemical Name hydrated potassium calcium silicate fluoride hydroxide
Chemical Formula KCa4Si8O20(F,OH).8H2O
Crystal System Tetragonal
Chemistry Classification Silicate

Apophyllite Colors

  • Colorless Apophyllite Colorless
  • Green Apophyllite Green

Alternate Names

Fisheye Stone, Apophyllite-(KF)

Countries of Origin

India

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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.