The International Gemological Institute has added IGI Diamond Typing, a new identification offering available at its New York laboratory. 

A diamond’s type is integral in determining the stone’s color and can distinguish likely candidates for HPHT color treatment process and/or artificial irradiation, IGI said in a statement. 

Diamonds fall into four major types, Ia, Ib, IIa and IIb, based on the concentration levels of nitrogen and/or boron in a given stone, as well as the state of aggregation of present nitrogen within its crystal lattice.

If a diamond is determined fit for color treatment, knowing the type aids in establishing the proper treatment conditions (temperature, pressure, irradiation, etc.) and assists in forecasting the color of the diamond after treatment.  

“Diamond typing is a crucial first step in the color treatment of diamonds and this new service can assist both our clients and the industry as a whole,” said IGI President and CEO Jerry Ehrenwald, GG, ASA.

In addition, diamond typing plays an important role in distinguishing true “Canary” diamonds (type Ib) and true Golconda diamonds (type IIa).

Customers can submit up to 10 diamonds, regardless of individual weight, to IGI’s New York laboratory at 589 Fifth Avenue) for typing, which costs $150. If fewer than 10 stones are submitted, the fee remains the same. The client will receive a document that attests to the type of each submitted diamond, in addition to its weight and measurements. Turnaround time for this service is 48 hours.

JCK