IGI Authentication
Independent expert verification for unauthenticated items from individual sellers, providing buyers with confidence and sellers with credibility
IGI — the International Gemological Institute — is an independent laboratory that physically examines and grades diamonds, gemstones, and jewelry. On GEMGEM, IGI authentication is used for items from individual sellers that have not yet been certified, providing buyers with an independent expert report before the item ships.
When IGI Authentication Applies
Understanding which items require independent verification
Items from Individual Sellers (Unauthenticated)
Pre-owned items listed by individual sellers that do not yet have an independent lab certificate or report.
IGI examines these items after your purchase is confirmed. You pay a 20% deposit at checkout, and the remaining balance after IGI verification passes.
Items from Individual Sellers (Pre-authenticated)
Pre-owned items that have already passed IGI or other recognized lab certification before listing.
These items are ready to ship immediately after full payment. No additional authentication needed.
Items from Partner Suppliers
Items from verified trade suppliers like RapNet.
For uncertified items USD 5,000+, GEMGEM sends for certification before shipping to you (GEMGEM absorbs this cost). Items under USD 5,000 or with existing certificates ship directly.
For Buyers
How IGI authentication protects your purchase
For unauthenticated items from individual sellers, IGI physically examines the stone or piece after your purchase is confirmed. IGI verifies the carat weight, cut, color, clarity, and metal authenticity.
If the report matches the seller's listing, your item ships to you. If there is a meaningful discrepancy, you have the option to adjust your offer or cancel with a full deposit refund.
Authentication Fee
You never pay the authentication fee. If the item passes, GEMGEM absorbs the cost. If the item does not pass, the seller is responsible.
The Process
Purchase Confirmed
You pay a 20% deposit. Seller ships item to IGI lab.
IGI Examination
Independent experts examine and grade the item (5-7 business days).
Results & Options
If matches: pay balance, item ships. If discrepancy: negotiate or cancel with full refund.
Delivery & Review
Item ships to you with 48-hour review window after delivery.
For Sellers
Understanding your authentication cost responsibility
Cost Responsibility
Transaction proceeds normally. GEMGEM absorbs the authentication cost. You receive your payment.
You are responsible for the authentication cost.
Transaction cancelled. Buyer receives full deposit refund. You bear the authentication cost and arrange item collection from lab within 14 days.
If you list an item as unauthenticated, GEMGEM covers the IGI authentication fee if your item passes inspection. The transaction proceeds normally and you receive your payment.
However, if IGI grades your item lower than your listing claimed and the buyer declines to proceed, you are responsible for the authentication cost.
Pre-authenticate to Avoid Uncertainty
Items with existing IGI or GIA certification can be listed immediately with their certificate or report details. This eliminates authentication delay and cost uncertainty, and makes your item eligible for the Fast Ship badge.
Authentication costs vary by item type, carat weight, and lab office location. Full fee tables are available in your seller dashboard.
What IGI Examines
Comprehensive verification for complete confidence
-
Carat Weight
Precise measurement to 0.01 carat
-
Cut Quality
Proportions, symmetry, and polish assessment
-
Color Grade
Standardized grading scale (D-Z for diamonds)
-
Clarity Grade
Internal and external characteristics assessment
-
Metal Authenticity
Composition verification for jewelry settings
-
Treatment Detection
Identification of enhancements or treatments
All IGI reports include detailed specifications, measurements, and high-resolution images of the examined item.
Ready to Buy or Sell?
Explore authenticated items or list your own with confidence
