Jedwabite

General Information:
 Chemical Formula:
Fe7(Ta,Nb)3
 Composition:
(Molecular Weight = 708.80 gm)
Tantalum 38.29 % Ta
Niobium 6.55 % Nb
Iron 55.15 % Fe
 Empirical Formula:
Fe0+7Ta1.5Nb0.5
 Environment:
Discovered in platiniferous placers in the Nizhnetagilsky District in the Middle Urals, in a collection made by P. Walther at the beginning of the 20th century, in association with niobocarbide and a tantalum carbide.
 IMA Status:
Approved IMA 1995
 Locality:
Nijniy-Tagil, near Solovjeva mountains (formerly Aurorinsky mine) and Baranchinsky massif near the Aktai River, Middle Urals, Russia.
 Name Origin:
For Jacques Jedwab, Universit‚ Libre de Bruxelles, Belgique, in recognition of his meticulous investigations of the mineralogy of placers and of carbides in natural environments.
Physical Properties:
 Cleavage:
None
 Color:
grayish yellow.
 Density:
8.6
 Diaphaniety:
Opaque
 Habits:
Granular - Generally occurs as anhedral to subhedral crystals in matrix., ,
 Hardness:
7 - Quartz
 Luster:
Metallic
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