Gahnospinel Value, Price, and Jewelry Information

Spinel - Locality: Hunza Valley, Gilgit District, Northern Areas, Pakistan. Size: 2.6 x 2.2 x 1.9 cm. A striking, 1.6 cm, lustrous, compound, octahedral, indigo-blue spinel crystal set atop contrasting snow-white marble from the Hunza Valley of Pakistan. Pristine, complete all-around and eminently viewable from both sides. By Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0], via Wikimedia Commons

Gahnospinel

Gahnospinel Value

Highest values go to pure blue, size and clarity.

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Spinel Value via Gem Price Guide

Accompanying value information:
3.60-ct spinel - spinel buying guide

Spinel Buying Guide

Spinel Gemstones - Sri Lanka

Spinel Value, Price, and Jewelry Information

Does Synthetic Spinel Exist? What is it?

Fine Color Blue: B 5/5
Blue .5 to 2 carats 2 to 4 carats 4 carats plus
Faceted to /ct to /ct to /ct
Fine Color Red: R, slpR 5/5
Red .2 to 1 carat 1 to 5 carats
Faceted to /ct to ,000/ct
Pink .5 to 1 carats 1 to 3 carats 3 carats plus
Faceted to /ct to ,000/ct to
Fine Color Purple: P 5/5: P, rP, bP, V 5/4
Purple .5 to 1 carats 1 to 3 carats 3 carats plus
Faceted to /ct to ,800/ct to ,000/ct
Fine Color Orange: O, rO 5/5
Other Colors .5 to 1 carats 1 to 5 carats 5 carats plus
Faceted to /ct to /ct to ,000/ct
Star Spinel All sizes
to /ct
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Gahnospinel Information

Data Value
Name Gahnospinel
Is a Variety of Spinel
Identifying Characteristics Dark tone
Formula (MgZn)Al2O4
Colors Green or blue, usually dark in tone
Fracture Conchoidal
Hardness 7.5 - 8
Cleavage Indistinct
Wearability Good
Crystallography Isometric.
Refractive Index 1.716-1.780
Birefringence None.
Dispersion 0.020
Luminescence Inert.
Luminescence Present No
UV Long Inert
UV Short Inert
Absorption Spectrum Bands at 5700 and 7000, not always present.
Pleochroism None.
Luster Vitreous.
Polish Luster Vitreous.
Fracture Luster Vitreous.
Specific Gravity 3.58-4.41
Enhancements None known.
Transparency Transparent to translucent
Phenomena None.

Gahnospinels from Sri Lanka

Gahnospinels from Sri Lanka

ZnO(%)

FeO(%)

N

S.G.

0.14

2.34

1.716

3.6

7.18

1.92

1.723

3.72

10.27

2.52

1.731

3.77

12.98

1.47

1.737

3.86

18.21

1.93

1.747

3.97

24.81

1.90

1.752

4.05

 

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by International Gem Society