Ekanite
Current inventory:  0 gems
 

  
Ekanite is named after F. L. D. Ekanayake who first found it in a Sri Lanka gravel pit.

Discovered in 1953;   IMA status:  Valid (IMA approved 1958)

Chemistry

Chemical Formula:

Ca₂ThSi₈O₂₀

Calcium Thorium Silicate

Molecular Weight:

856.87 gm

Composition:

Calcium

9.35 %

Ca

13.09 %

CaO

Thorium

27.08 %

Th

30.81 %

ThO₂

Silicon

26.22 %

Si

56.10 %

SiO₂

Oxygen

37.34 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Silicates (Germanates)

Strunz 8th Ed. ID:

8/E.10-10

Nickel-Strunz 10th Ed. ID:

9.EA.10

9 : SILICATES (Germanates)
E : Phyllosilicates
A : Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings

Related to:

None

Members of Group:

None

Varieties:

None

Synonyms:

None

Crystal Data

Crystallography:

Tetragonal - Trapezohedral (may be metamict)

Crystal Habit:

Poorly-formed pyramidal crystals, to 1 cm, as clusters of grains; rounded massive.

Twinning:

None

Physical Properties

Cleavage:

Distinct on [101], indistinct on [001]

Fracture:

Irregular, Uneven

Tenacity:

Brittle

Moh's Hardness:

5.0 - 6.5

Density:

3.28 - 3.32 (g/cm³)

Luminescence:

None

Radioactivity:

Strong; GRapi = 542,060.77 (Gamma Ray American Petroleum Institute Units)

Other:

May be metamict due to radiation.

Optical Properties

Color:

Colorless, Yellow, Light to Dark Green, Brown, Red from inclusions

Transparency:

Transparent to Translucent

Luster:

Vitreous

Refractive Index:

1.590 - 1.596  Uniaxial ( - )

Birefringence:

0.0120

Dispersion:

n/a

Pleochroism:

n/a

Occurances

Geological Setting:

Detrital (Sri Lanka); in a glacial erratic syenitic boulder (Tombstone Mountains, Canada); in volcanic ejecta (Case Collina, Italy).

Common Associations:

Fluorite, Garnet, Quartz, Microcline, Clinopyroxene, Apatite, Sodic Plagioclase, Hematite, Thorogummite, Zircon, Titanite (Tombstone Mountains, Canada); Quartz, Feldspar, Pyroxene (Case Collina, Italy).

Common Impurities:

U, Fe, Pb, Al, Mn, Pb, Mg

Type Locality:

Ehiliyagoda (Ehaliyagoda), Ratnapura, Sabaragamuwa Province, Sri Lanka

Year Discovered:

1953 (IMA approved 1958)

View mineral photos:

Ekanite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Ekanite is an extemely rare gem. It was discovered in 1953 in the gem gravels at Eheliyagoda, near Ratnapura, Sri Lanka. It is also found at Mt. Sainte Hilaire, Quebec, Canada. Ekanite may be strongly radioactive as defined in 49 CFR 173.403 (greater than 70 Bq/gram) due to the presence of Thorium (Th). Ekanite is almost always completely metamict. Metamictization is a natural process due to radiation bombardment that results in the gradual and eventually complete destruction of a mineral's crystal lattice leaving the mineral amorphous. Ekanite is found in shades of green and brown as are other metamict gems such as low Zircon and Sphene.
 

  
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