The IGI, International Gemological Institute, issues a Grading Summary, which is an independent verification of a piece of jewellery suitable with your receipt of purchase for insurance purposes. The GIA, Gemological Institute of America, issues Diamond Grading Reports. This is a complete technical description of the diamond as it is loose, prior to being mounted in the setting. Neither the Grading Summary nor the GIA assign any monetary value to the diamond, just specific measurements and quality grades, identifying a particular diamond versus any other. If a diamond has a Diamond Grading Report from the GIA, the IGI will reference that report in its Grading Summary.

Costco guarantees diamond clarity to be VS-2 (Very Slightly Included) and colour to be I (Near Colourless) or better. To ensure our quality is never compromised and our orders are prompt, our vendors often supply us with higher quality diamonds. Our gemologists check every diamond to ensure our minimum quality is met.

Coloured stone cutting is not an exact science. When listing a piece of coloured stone jewellery we guarantee a minimum millimetre size. Most coloured stones are bought and sold according to a calibrated millimetre size because carat weights can vary widely.

No. Item selection on Costco.ca generally differs from the warehouse selection. We do not have the procedures in place to track jewellery shipped to a warehouse for preview.