Natural diamonds
Type IIa stones command a premium again
Chemically pure Type IIa natural diamonds are pricing above ordinary D-to-F stones as cutters report fewer rough parcels yielding them.
Imperial Star Gems trade desk1 min read
Type IIa rough has thinned out, and polished Type IIa is pricing above ordinary colourless stones of the same grade.
- Cutters report fewer parcels yielding Type IIa rough, the chemically purest class of natural diamond, prized for its exceptional transparency.
- Polished Type IIa stones in D to F colour are now pricing several points above ordinary stones of the same colour and clarity.
- The premium is most visible from 1 ct upward, where a grading report noting the classification adds resale confidence.
Type IIa is a classification, not a grade, so it sits alongside colour and clarity rather than replacing them — see colour grade and grading report for how the two interact. Buyers chasing maximum transparency at a given size should ask specifically whether a stone has been tested for it. Browse natural stock.
Market commentary drawn from publicly available market data and trade reporting, not investment advice. Prices move; figures are indicative and correct as of the date above.