Sorting and Grading Coloured Gemstones

of Coloured Gemstones

Gemfields’ proprietary grading system is key to the modernisation of the coloured gemstone industry and the success of auctions. Buyers can now have confidence in their purchases and design increasingly ambitious colourful jewellery creations.

Sorting and Grading Emeralds

Before Gemfields acquired Kagem in 2008, in partnership with the Zambian government, sorting and grading systems for emeralds were inconsistent. Buyers bought bags of mixed-quality gemstones.

Gemfields’ proprietary grading system sorts gems into more than 200 grades, giving buyers more confidence in their purchase.

Lots of similar size, colour and clarity are sold for the highest price at invitation-only auctions, with all proceeds fully repatriated to Zambia.


Sorting and Grading Rubies

When grading a ruby, colour is crucial. The primary hue must be red, but secondary hues can be pink, orange and purple.

Rubies from different origins often have distinctive hues, but Mozambican rubies span all known colour ranges, including the rarest pure fluorescent reds. They also have the most sought-after characteristics that make a ruby desirable: fluorescence, colour and clarity perfection.