3.69 ct. Stibiotantalite
Color: Medium Dark Very Slightly Brownish-Yellow
Clarity: Slightly to Moderately Included
Cut: Rectangular Radiant
Measurements: 6.4 x 5.6 mm
It is extremely difficult to source any Stibiotantalite over 1 carat in weight, let alone a 3+ carat gem that approaches this level of clarity. Nearly all the stones left in the market are old stock and there is little if any new material coming from the well-known deposit. This gorgeous example has all the best qualities of the material and is extremely well cut - not even a hint of being shallow or asymmetric as is often the case with these. Moreover, though it remains slightly included, the clarity is overall extremely respectable for Stibiotantalite; the typical gem is so included as to be nearly opaque.
An exceptionally interesting 'rare gem' material, Stibiotantalite has one of the highest refractive indexes in the gem world (2.37-2.45) and a very high specific gravity at around 6.7 (vs. 4.6 for Zircon and 3.5 for Diamond). Furthermore, it has a great color, is reasonably hard and is capable of taking a great polish. This is a fantastic collection stone and very hard to beat for the size (huge for the species) and cost.