Lab-grown diamonds should be sold with second-tier reports giving details of their manufacture, rather than 4C gradings according to CIBJO. The purpose is to preserve the distinction between manufactured diamonds and natural diamonds for which rarity is a critical factor. CIBJO has released a Laboratory Grown Diamond Guidance document, the final stage of a two-year process to standardize the lab-grown sector and boost consumer confidence. Lab-grown reports will include the name of the manufacturer, the production batch, country of origin, method of manufacture (HPHT or CVD), and information about any treatments and processes the diamond has undergone--all of which reinforce the message that the diamond was made, not mined. If the 4Cs are used to describe the physical characteristics of lab-grown diamonds, the letters 'LG' will be placed as a prefix before color and clarity. I hope it works.
Useful link: http://www.cibjo.org
