
How we identify pearls!
IGL applies the same item identification and tracking procedures to all pearls, as it does for colored stones and diamonds. Each item is assigned a bar-coded label with a unique internal identification number that is used to track it throughout the process.
At every step, special inspection, care, and handling procedures ensure items are managed with the utmost care.
Weight Verification
This is the first stop for any item submitted for pearl services. Pearls are counted by hand and then weighed with an electronic micro-balance that captures the weight in grams (mounted or strung), carats (loose), or carats and grains (loose natural). Pearls are measured using special digital calipers.
Identifing pearl types
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. The gemologist identifies pearl types, mollusks and any detectable treatments using the standard gemological testing and advanced testing equipment, including real-time x-radiography, UV-Vis reflectance spectroscopy and XRF. Real-time x-radiography equipment is used to measure the nacre thickness of bead-cultured pearls.
Color Identification
The gemologist determines color and classifies the other factors under a controlled viewing and lighting environment, using a comprehensive set of pearl masters. The pearl master sets include a hue circle and various color grids to determine color, and type-specific master sets of strands to classify luster, surface and matching.



