According to multiple media sources, the diamond grading laboratory has implemented lower-cost fees for this service in order to create “a more affordable screening option for clients”.

The Gemological Institute of America (GIA)’s quality assurance is available for loose and mounted diamonds – specifically D to Z grade and coloured diamonds that weigh 0.20 carats or less, and black diamonds that are 5 carats or less.

In addition to determining whether a diamond is natural or synthetic, as well as if it has undergone colour treatment, the service tests for clarity treatment, diamond type, gemstone material and surface treatment.

Under the new fee structure, the service will cost US$10 (AU$11) per stone for diamonds between 0.06 and 0.20 carats, while diamonds that are 0.05 carats or smaller will cost US$5 (AU$6) per stone.

According to the GIA’s website, the service is being offered in response to an increase in the number of treated and synthetic diamonds finding their way into various supply channels.

Jeweller has previously reported on numerous cases of undisclosed synthetic diamonds, including an incident in Australia earlier this year whereby Sydney-based Gem Studies Laboratory (GSL) discovered a parcel of synthetic yellow diamonds.

The GIA, which was established in 1931, founded the International Diamond Grading System. It grades both diamonds and gemstones through nine laboratories located in Carlsbad, New York, Mumbai, Hong Kong, Bangkok, Johannesburg, Gaborone, Israel and Tokyo.