Home › Guides › IGI Certificate Guide: How to Read and Verify a Lab Grown Diamond Report Lab grown diamond guide IGI Certificate Guide: How to Read and Verify a Lab Grown Diamond Report The certificate (grading report) is your proof of what you are buying. It takes two minutes to read and one minute to check online. Here is how. By Vinay Mutha, in the diamond trade in Zaveri Bazaar, Mumbai since 1999 · Updated 6 Nov 2026 On this pageWhat IGI isWhat is on an IGI lab grown diamond reportHow to verify the report in one minuteWhat about GIA?Certificate vs hallmarkShop certified diamonds What IGI is IGI (International Gemological Institute) is one of the largest diamond grading labs in the world, with labs in India including Mumbai. Most lab grown diamonds in the market are graded by IGI. An IGI report is an independent opinion of the stone's quality – it is not issued by the seller. What is on an IGI lab grown diamond report Report number – unique to your stone. It is also laser inscribed on the diamond's girdle. Description – clearly says "Laboratory Grown Diamond". Shape and cutting style – for example Round Brilliant, Oval Brilliant, Emerald Cut. Measurements – length × width × depth in millimetres. Carat weight – weight, not size. See our 4Cs guide. Colour grade – D (colourless) downwards. Clarity grade – FL/IF, VVS1, VVS2, VS1, VS2, SI1 and so on. Cut, polish and symmetry – Ideal / Excellent / Very Good / Good. Fluorescence – glow under UV light; "None" is most common. Growth method – CVD or HPHT, and a note on any post-growth treatment ("As Grown" means none). Inscription – the text lasered on the girdle, usually "LG" plus the report number. How to verify the report in one minute Open the IGI website (igi.org) and go to "Verify Your Report". Type the report number from your certificate. Check that shape, carat weight, measurements, colour and clarity on the screen match the paper copy and what you were sold. With a 10× loupe, the jeweller can show you the same number inscribed on the girdle. If anything does not match, do not pay until it is explained. We share the report number of every certified diamond before you order. What about GIA? GIA changed how it reports lab grown diamonds. From 1 October 2025 GIA stopped using the D–Z colour and FL–I clarity scale for lab grown stones. Instead it describes them as "Premium" or "Standard", and stones below its Standard level get no GIA assessment. So for lab grown diamonds, an IGI report gives you the most detail about your exact stone's colour and clarity. Certificate vs hallmark The IGI report is for the diamond. The gold has its own proof: in India, gold jewellery carries a BIS hallmark with a 6-digit HUID code. Read 14K vs 18K gold and the BIS hallmark. Shop certified diamonds Every loose diamond on our site shows its lab and report details. Start with round, oval or emerald lab grown diamonds. Frequently asked questions How do I check an IGI certificate online?Go to igi.org, open "Verify Your Report", enter the report number and compare the shape, weight, measurements, colour and clarity with your paper report.Is the IGI number on the diamond itself?Yes. IGI laser inscribes the report number (and usually "LG") on the girdle of a lab grown diamond. It can be seen with a 10× loupe.Does GIA still grade lab grown diamonds on D–Z colour?No. Since 1 October 2025 GIA describes lab grown diamonds only as "Premium" or "Standard" instead of using the D–Z colour and clarity grades. More guidesLab Grown vs Natural Diamonds: What Is Really Different?How Are Lab Grown Diamonds Made? CVD and HPHTThe 4Cs of Lab Grown Diamonds, Made Simple14K vs 18K Gold: Which Is Better for Your Diamond Jewellery?Diamond Shapes Guide: Find the Shape You LoveHow to Clean and Care for Your Diamond Jewellery