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Sogdianite
Current inventory:  1 gem
 

Sogdianite

Chemistry:  K1.5Na0.5Li1.8Fe3+0.9Al0.3ZrSi12O30

Discovered in 1968;   IMA status: Approved (1968).
Sogdianite is named for
Sogdiana, an ancient Central Asian state.

 

Classification

   

   

Mineral Classification:

Silicates

Strunz 8th Ed. ID:

8/E.22-120

 

8 : Silicates
E : Cyclosilicates, triplet rings [Si3O9]6-
22 : Millarite - Osumilite series

 

 

Crystal Data

   

   

Crystallography:

Hexagonal - Dihexagonal Dipyramidal

Crystal Habit:

Crystals are Tabular, to 1 cm; in platy aggregates, to 15 cm.

Twinning:

None

 

 

Physical Properties

   

 

Cleavage:

[0001] Perfect

Fracture:

Sub-Conchoidal to Uneven

Tenacity:

Brittle

Moh's Hardness:

5.0 - 7.0 (7.0 if pure)

Density:

2.76 - 2.90 (g/cm3)  (2.90 if pure)

Luminescence:

Fluoresces dark violet under LW UV and very dark red under SW UV.

Radioactivity:

Barely Detectable, GRapi = 79.14 (Gamma Ray American Petroleum Institute Units)

 

 

Optical Properties

   

   

Color:

Violet

Transparency:

Transparent to Translucent

Luster:

Vitreous to Waxy

Refractive Index:

1.606 - 1.608  Uniaxial ( - )

Birefringence:

0.0020

Dispersion:

n/a

Pleochroism:

None

 

 

Occurances

   

   

Geological Setting:

In a pegmatite vein with a composition about that of an alkalic granite.

Type Locality:

Dara-i-Pioz Glacier, Alayskiy (Alai) Range, Tien Shan Mts, Districts of the Republican Subordination, Tajikistan

Year Discovered:

1968

 

 

More Information

   

   

 

Mindat.org
Webmineral.com

 

 


Sogdianite is a extremely rare gem. There are only three know sources:
 the Dara-i-Pioz massif, Alai Range, Tien Shan, Tajikistan; the Wessels mine, near Kuruman, Cape Province, South Africa; at Washington Pass, Okanogan Co., Washington, USA. Sogdianite is often mixed with other minerals so the specific gravity and hardness are variable. It is closely related to Sugilite.
 

  
Sogdianite gems for sale:

Sogdianite-001

Gem:

Sogdianite

Stock #:

SOGD-001

Weight:

0.419 ct

Size:

6.56 x 3.79 x 2.03 mm

Shape:

Rectangle

Color:

Violet

Clarity:

Translucent

Origin:

Tien Shan, Tajikistan

Treatment:

None (natural)

Price:

SOLD

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

Sogdianite-001A

This extemely rare gem is from Tajikistan. The color is an intense violet.


 

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