Identification Steps

GIA receives a varied and complex range of items submitted for identification; everything from colored stones and pearls, unusual carvings and jewelry, to the latest in synthetics, and simulants, as well as treated gems. A significant area of activity involves the origin of color in gemstones, most notably, but far from limited to, diamonds, rubies, and sapphires.

Inspection, Care, and Handling Procedures
GIA applies the same item identification and tracking procedures to gem identification as it does to diamond grading. Each gem is assigned a bar-coded label with a unique internal identification number that is used to track the item throughout the laboratory. And at every step of the gemological identification process, special inspection, care, and handling procedures serve to confirm an item’s identity and ensure it is managed with the utmost care.

Weights and Measures
This is the first stop for any gemstone. Loose gems are weighed with an electronic micro-balance that captures the weight to the fifth decimal place. Loose polished stones are also measured with an optical measuring device to determine their proportions, measurements and facet angles. Mounted stones are measured, but not weighed.

Identification
Items are then transferred to the Identification Inventory Control department for distribution to trained and experienced gemologists for servicing. Once an item is received by an initial gemologist, its recorded weight and measurements are verified, or if the item is mounted or strung, the gemologist will use manual measuring devices to determine and record necessary measurements.

The gemologist then performs a variety of analytical investigations, including a microscopic examination of the item, and performs all the tests required to properly determine its gemological identity and detect any treatments. To learn more about the state-of-the-art technology GIA gemologists use in their Research and Identification Service efforts, please click here.

After that, the item is transferred to a second gemologist, who independently performs all necessary observations and testing. Depending on the identity and nature of the item, it may be examined by additional gemologists and research specialists.

Report Processing and Item Return
Reports are generated after all results are finalized and services have been completed. All GIA Reports are examined and proofread to ensure quality and proper assembly before being sent to the client.

Last, the item is placed in its original container, joined with its report, and goes through a final inspection and testing to ensure that the same submitted item is returned to the client. 

Items are returned either in person through the Client Services department or via courier through the Transport Services department. All information recorded for an item remains stored in GIA's permanent database for future reference.

For information on how you can become a well-informed colored stone buyer, click here and complete GIA’s interactive tutorial.