Published May 2009

By Richard B. Drucker, GG

If you are not familiar with this gemstone, zultanite is a change of color diaspore from Turkey. The color change observed is a pink to green. New information reveals that in many experiments with cutting, the color change occurs when cut along any axis, unlike most color change gems. Should you encounter a zultanite for appraisal, be aware that this is a branded gemstone and as such, it should be researched and priced accordingly. The brand has been established by Zultanite Gems, LLC to distinguish their product from what they claim to be stolen material from the mine that occasionally surfaces. Most other material that does show up is inferior in clarity and in cut according to the company. Zultanite Gems cuts to higher standards and has a very low yield from the rough of only 2-3%.

Zultanite properties are as follows. Note that these properties are from the current zultanite deposits and differ slightly from previous diaspore deposits.
 
Crystal Structure: Orthorhombic
Refractive Index: 1.70-1.75
Birefringence: 0.048
Specific Gravity: 3.39
Moh’s Hardness: 6 ½ -7
Color: Color change from light green to purplish pink or brownish pink
Clarity: Usually eye-clean
Cut: Standard shapes and custom cuts
Enhancements: None
Care: No heat, no ultrasonic

When considering the above properties, it is interesting that zultanite is not recommended for ultrasonic cleaning. I asked Jim Fiebig, Global Sales Director, for an answer on the durability issue with ultrasonic cleaners. He stated, “We have no absolute science concerning ultrasonic effect on zultanite. It is not the inclusions since virtually all genuine zultanite is quite clean. So far, we know HOT ultrasonic cleaners will cleave zultanite on the C-axis where the single direction of perfect cleavage is. Thermal shock in general seems to be the most destructive force for us. Our cutters even try to orient each crystal so the plane of cleavage is at least 25 degrees away from the girdle and that has proven effective in preventing setting and normal wear issues. So, the ‘no ultrasonic cleaners’ is more for safety, since most cleaners do heat up by the end of the day.”

Knowing this, jewelers must be cautious in doing repairs and cleaning, just as they would with emeralds or tanzanite. However, wearability and durability are very good for this gem and typically pose no problems for jewelry settings of any kind.

This gem occurs in many sizes. A current price chart follows.
1.00 ct. to 2.99 ct.        $200/ct.
3.00 ct. to 6.99 ct.        $300/ct.
7.00 ct. and over          $400/ct.
Cabochons                   $40/ct.
Prices are for eye clean, lightly included stones. Moderately included are -25%; heavily included are -50%. All cabochons are included.

For more information go to www.zultanite.com.

For more in-depth articles on the gem industry and reliable wholesale pricing, order a GemGuide subscription. For the fastest appraisal software in the industry, guaranteed to save you time and money, fully integrated with pricing and all weight formulas, go to GemGuide Appraisal Software..

Back to Previous Page