Diamond Jewellery in Gurugram | BIS Hallmark Collection For buyers, jewellery professionals, and entrepreneurs looking to go deeper, the Indian Institute of Gemology offers practical, hands-on training in diamond grading and gem identification — trusted by the trade since 1991. With alumni across India and abroad, IIG's courses can truly transform how you see and shop diamonds. https://iigdelhi.com/diamond-jewellery-in-gurugram-bis-hallmark-collection/