IGI Certification & Diamond Quality

IGI stands for the International Gemological Institute, an independent gemmological laboratory. Its Laboratory Grown Diamond Report identifies a diamond's laboratory-grown origin and records its assessed characteristics.

The report documents the individual stone, including carat weight, colour, clarity, shape, measurements, polish and symmetry, and a cut grade where applicable.

For a design combining a certified centre diamond with pavé, the report covers the centre diamond only. A piece made entirely with pavé or diamonds below 0.30 ct does not come with an IGI certificate.

• Lab-grown diamonds of 0.30 ct and above: an individual IGI certificate accompanies each stone, excluding pavé diamonds.
• Diamonds below 0.30 ct: no individual IGI certificate.
• Pavé diamonds: no individual IGI certificates.

Diamond quality is described through four internationally recognised characteristics: cut, colour, clarity and carat.

• Cut: proportions and workmanship that influence how a diamond interacts with light.
• Colour: for white diamonds, the D-Z scale starts with D, the most colourless grade.
• Clarity: internal inclusions and surface characteristics assessed under 10x magnification.
• Carat: the diamond's weight. CTW means combined carat weight for a piece or pair.

We select our lab-grown diamonds within defined quality specifications. For individually certified diamonds, the IGI report records the stone's specific grades.

• Colour: G-J, near colourless.
• Clarity: VS2 or better.
• Cut: Excellent or better, where an overall cut grade applies.

Lab-grown diamonds have the same chemical composition, crystal structure and essential optical and physical properties as natural diamonds. Like natural diamonds, individual stones vary in colour, clarity and cut quality; IGI assesses them using the 4Cs.

At Hartenstein Diamonds, proportion and brilliance inform our diamond selection. Our jewellery is crafted on demand in Antwerp and checked for proportion, comfort and setting security before delivery.

In pavé, small diamonds are set close together to create a continuous sparkling surface. These diamonds do not receive individual IGI reports under our policy.

The absence of an individual report does not, by itself, indicate lower quality. It means that a separate laboratory grading document is not supplied for each stone.