Ekanite

Ekanite is green to brown colored rare stone with chemical composition calcium thorium silicate.

Thorium is a highly radio active element and due to this element Ekanite is converted to metamict state. In metamict state Ekanite almost acts like amorphous. By applying heat at certain temperature the metamict state of Ekanite can be restored to crystalline state.

The main source for Ekanite is Sri Lanka and Canada.

Ekanite Properties

Chemical Composition: 
Calcium Thorium Silicate - ThCa2Si8O20
Classification / Type: 
It is a metamict mineral.
Colors / Varieties: 
  • Green, brown (metamict)
  • Yellow, red (crystalline)
  • Four rayed star
Crystal System / Forms: 
Tetragonal System / Prismatic crystals and water-worn pebbles.
Hardness: 
6 - 6.5
Specific Gravity: 
3.28
Cleavage / Fracture: 
None / Conchoidal.
Optic Character: 
Anisotropic, D.R.; Uniaxial negative. Is almost amorphous and appears Isotropic (S.R.) due to metamict state.
Lustre: 
Vitreous.
Refractive Index / Birefringence: 
  • Metamict: 1.597
  • Crystalline: 1.568 - 1.580 / 0.012
Pleochroism: 
Not common.
Magnification: 
Crystalline inclusions.
U.V. Fluorescence: 
Variable.
Spectrum: 
Not characteristic.
Treatment (Enhancement): 
Heat treatment restores crystalline state.
Specific Tests: 
Highly radioactive.
Simulants (with separation tests): 
Moldavite (R.I., S.G., inclusions), Brazilianite (optic figure, R.I., birefringence).
Geological Occurrence: 
Alluvial deposits.
Sources: 
Sri Lanka, Canada.
Cuts & Uses: 
Facetted, cabochon, etc.