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Microlite
Current inventory: 2 gems
 

Microlite

Chemistry:  BeAl2O4 + (Na,Ca)2Ta2O6(O,OH,F)

Discovered in 1835;   IMA status: Valid (pre-IMA; Grandfathered).
Microlite gets its name is from the Greek words mikros meaning small, and lithos meaning stone; due to the very small size of the crystals found at the original locality.

 

Classification

   

   

Mineral Classification:

Oxides

Strunz 8th Ed. ID:

4/C.18-10

 

4 : Oxides & Hydroxides
C : Oxides with metal : oxygen = 2:3 (M2O3 and related compounds)
18 : Pyrochlore group, Microlite series with Ta > Nb

 

 

Crystal Data

   

   

Crystallography:

Isometric - Hexoctahedral

Crystal Habit:

Commonly as euhedral to subhedral octahedra, modified by the dodecahedron, cube, to 8 cm; also granular, massive. Twinning: Rare, according to the spinel law, twin plane.

 

 

Physical Properties

   

 

Cleavage:

[111] Poor

Fracture:

Irregular, Uneven, Splintery, Sub-Conchoidal

Tenacity:

Brittle

Moh's Hardness:

5.0 - 5.5

Density:

4.20 - 6.4 (g/cm3)

Radioactivity:

Not Radioactive

 

 

Optical Properties

   

   

Color:

Yellow, Pale yellow to reddish brown, sometimes emerald-green

Transparency:

Opaque to Translucent, Transparent in thin fragments

Luster:

Vitreous to Adamantine, Resinous on fractures

Refractive Index:

1.93 - 2.02  Isotropic

Birefringence:

0.00 (Isotropic)

Dispersion:

n/a

Pleochroism:

None

 

 

Occurances

   

   

Geological Setting:

A primary mineral in lithium-bearing granite pegmatites, or replacing tantalum minerals; in miarolitic cavities in granites.

Type Locality:

Clark Ledges pegmatite locality, Chesterfield, Hampshire Co., Massachusetts, USA

Year Discovered:

1835

View mineral photos:

Microlite Mineral Photos and Locations

 

 

More Information

   

   

 

Mindat.org
Webmineral.com

 

 


Microlite is a very rare member of the Pyrochlore group of minerals. As a mineral, it is usually opaque to translucent and plentiful in some locations. Gem quality crystals however are quite rare and very small so faceted gems tend to be small and are extremely rare. Microlite is a beautiful gem that is found in colors of pale to bright yellow, brown, reddish and green. Current sources of gem grade Microlite are the Alto do Giz pegmatite, and Virgem da Lapa, Minas Gerais, Brazil.  

  
Microlite gems for sale:

Microlite-002

Gem:

Microlite

Stock #:

MICRO-002

Weight:

0.5405 ct

Size:

4.36 x 4.26 x 2.56 mm

Shape:

Trillion

Color:

Yellow

Clarity:

SI

Origin:

Virgem da Lapa M.S., Brazil

Treatment:

None (natural)

Price:

$162.00    [ Make an offer ]

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Microlite-002

This rare Microlite is very bright yellow and large for the type. This gem is from Virgem da Lapa, Jequitinhonha valley, Minas Gerais, Brazil.


Microlite-001

Gem:

Microlite

Stock #:

MICRO-001

Weight:

0.321 ct

Size:

3.38 x 2.38 mm

Shape:

Round

Color:

Yellow

Clarity:

Eye Clean - SI

Origin:

Virgem da Lapa M.S., Brazil

Treatment:

None (natural)

Price:

$96.00    [ Make an offer ]

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Microlite-001

This rare Microlite is very bright yellow and is eye clean with slight inclusions visible under loupe. This gem is from Virgem da Lapa, Jequitinhonha valley, Minas Gerais, Brazil.


 

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