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Hyalophane  (variety of Feldspar)
Current inventory:  0 gems
 

Hyalophane

Chemistry:  (K,Ba)Al(Si,Al)3O8

Discovered in 1855;   IMA status: Valid (pre-IMA; Grandfathered).
The name Hyalophane is from the Greek words hyalos - "glass" and phanos - "to appear" in allusion to the transparency of its crystals.

 

Classification

   

   

Mineral Classification:

Silicates

Strunz 8th Ed. ID:

8/J.06-50

Nickel-Strunz 10th Ed. ID:

9.FA.30

 

9 : SILICATES (Germanates)
F : Tektosilicates without zeolitic H
2O
A : Tektosilicates without additional non-tetrahedral anions

Related to:

Feldspar Group;

Celsian-Hyalophan Series,

Hyalophane-Orthoclase Series

 

 

Crystal Data

   

   

Crystallography:

Monoclinic - Prismatic

Crystal Habit:

Crystals similar to Adularia or Orthoclase, to 20 cm; also granular or massive.

Twinning:

Commonly simple twins according to the Carlsbad, Manebach, or Baveno laws.

 

 

Physical Properties

   

 

Cleavage:

[001] Perfect, [010] Imperfect

Fracture:

Uneven, Conchoidal

Tenacity:

Brittle

Hardness (Mohs):

6.0 - 6.5

Density:

2.58 - 2.82 (g/cm3)

Luminescence:

None

Radioactivity:

Barely Detectable, GRapi = 9.71 (Gamma Ray American Petroleum Institute Units)

 

 

Optical Properties

   

   

Color:

Colorless, White, pale Yellow, Red

Transparency:

Transparent to Translucent

Luster:

Vitreous

Refractive Index:

1.542 - 1.547  Biaxial ( - )

Birefringence:

0.005

Dispersion:

Weak; r > v

Pleochroism:

None

 

 

Occurances

   

   

Geological Setting:

Typically associated with metamorphosed manganiferous rocks or in mineral deposits rich in manganese.

Common Associations:

Manganiferous Epidote, Rhodonite, Rhodochrosite, Spessartine, Manganiferous Tremolite, Plagioclase, Analcime.

Type Locality:

Lengenbach Quarry, Im Feld (Imfeld; Feld; Fäld), Binn Valley, Wallis (Valais), Switzerland

Year Discovered:

1855

View mineral photos:

Hyalophane Mineral Photos and Locations

 

 

More Information

   

   

 

Mindat.org
Webmineral.com

 

 


Hyalophane is very rare gemstone and a member of the Feldspar Group of minerals that also includes Albite, Amazonite, Andesine, Anorthite, Bytownite, Hyalophane, Labradorite, Moonstone, Oligoclase, Orthoclase, Sanidine and Sunstone. It is usually found as translucent to opaque crystals of colorless, white or pale yellow. Crystals are rarely found clean enough for faceting.

The only current source of these rare crystals is Busovaca, Bosnia.
 

  
Hyalophane gems for sale:

We have not photographed our Hyalophane gems yet.  Please check back soon!
 

 

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