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Cleavelandite  (a variety of Albite) (inclusions in Quartz)
Current inventory:  0 gems
 

Cleavelandite inclusion in Quartz

  
Cleavelandite is named after Parker Cleaveland, a professor of geology and mineralogy at Bowdoin College in Maine during the early 1800s.

Discovered in 1815 (Albite).   IMA status: Not Valid (Cleavelandite is a variety of Albite)

 

Chemistry

 

 

Chemical Formula:

Na[AlSi3O8]

 

Sodium Aluminum Silicate

Molecular Weight:

263.02 gm

Composition:

Soldium

8.30 %

Na

11.19 %

Na2O

 

Calcium

0.76 %

Ca

1.07 %

CaO

 

Aluminum

10.77 %

Al

20.35 %

Al2O3

 

Silicon

31.50 %

Si

67.39 %

SiO2

 

Oxygen

48.66 %

O

 

 

 

 

100.00 %

 

100.00 %

= TOTAL OXIDE

 

 

Classification

   

   

Mineral Classification:

Silicates (Germanates)

Strunz 8th Ed. ID:

8/J.07-20

Nickel-Strunz 10th Ed. ID:

9.FA.35

 

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

Related to:

Variety of Albite. Feldspar Group. Plagioclase Series. Na-rich end member of the Albite-Anorthite Series. Low- and high-temperature structural modifications exist. Low- and high-temperature structural modifications are recognized.

Synonyms:

Clevelandite

 

 

Crystal Data

   

   

Crystallography:

Triclinic - Pinacoidal

Crystal Habit:

(Albite) Crystals commonly tabular || {010}, may be curved, to 3 cm; divergent aggregates, granular, cleavable massive.

Twinning:

(Albite) Common around [010] or {010}, giving polysynthetic striae on {001} or {010}; many other laws, contact, simple and multiple.

 

 

Physical Properties

   

 

Cleavage:

Perfect on {001}, very good on {010}, imperfect on {110}

Fracture:

Irregular/Uneven to Conchoidal

Tenacity:

Brittle

Moh's Hardness:

6.0 - 6.5

Density:

2.60 - 2.65 (g/cm3)

Luminescence:

Fluorescent, Short UV=cherry-red blue, Long UV=white.

Radioactivity:

Not Radioactive

Other:

F

 

 

Optical Properties

   

   

Color:

White to Gray, Bluish, Greenish, Reddish; may be chatoyant.

Transparency:

Transparent to Translucent

Luster:

Vitreous, Pearly on cleavages

Refractive Index:

1.528 - 1.542  Biaxial ( + ), Biaxial ( - ) for high variety

Birefringence:

0.0090 - 0.0100

Dispersion:

Weak; r < v

Pleochroism:

None

 

 

Occurances

   

   

Geological Setting:

A major constituent of granites and granite pegmatites, alkalic diorites, basalts, and in hydrothermal and alpine veins. A product of potassium metasomatism and in low-temperature and low-pressure metamorphic facies and in some schists. Detrital and authigenic in sedimentary rocks.

Common Associations:

Quartz, Orthoclase, Muscovite, Biotite, "Hornblende"

Common Impurities:

Ca, K, Mg

Type Locality:

(Albite) Finnbo (Finbo), Falun, Dalarna, Sweden

Year Discovered:

(Albite) 1815

View mineral photos:

Cleavelandite Mineral Photos and Locations

 

 

More Information

   

   

 

Mindat.org  (Cleavelandite)
Mindat.org  (Albite)
Webmineral.com  (Albite)

 

 


Cleavelandite is a platy variety of Albite which is a member of the Feldspar Group of minerals that includes Albite, Amazonite, Andesine, Anorthite, Bytownite, Hyalophane, Labradorite, Moonstone, Oligoclase, Orthoclase, Sanidine and Sunstone. Cleavelandite is not a gemmy variety but forms a very attractive inclusion in Quartz. Round, white "snow ball" Cleavelandite inclusions in faceted Quartz are very collectable. Although Albite is widespread, Cleavelandite inclusions in Quartz are relatively rare. The best source seems to be Minas Gerais, Brazil.
 

  
Cleavelandite gems for sale:

We have not photographed our Cleavelandite gems. Please check back soon.
 

 

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