Gahnospinel Value, Price, and Jewelry Information

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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.

The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.

Spinel Value via Gem Price Guide

Accompanying value information:

Spinel Buying Guide

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 ,250/ct	to ,500/ct	,200 to ,500/ct

Fine Color Red: R, slpR 5/5

Red	.2 to 1 carat	1 to 5 carats
Faceted	to ,000/ct	to ,000/ct

Pink	.5 to 1 carats	1 to 3 carats	3 carats plus
Faceted	to ,800/ct	to ,000/ct	to ,500

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 ,000/ct	to ,000/ct

Star Spinel	All sizes
	to /ct

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