Rarity and Availability of Gemstones and Coloured Diamonds
Due to marketing and trade patterns, there is a bit of competition between traditional gemstones and coloured diamonds.
Supply is definitely a factor. In one of the estimates, it is said that less than 2% of all gemstones are can be considered fancy coloured diamonds, while white and colourless diamonds are so common that they are considered mass market consumer goods. This is especially true among smaller carat sizes.
The rarity of fancy coloured diamonds allows for some of them to go for more than £100,000 per carat. In fact, at private invitation on auctions by some of the mines, bids of more than £200,000 have been reported for fancy pink and reddish coloured diamonds. It has been a passionate fight among connoisseurs for such stones as they are widely regarded as the non plus ultra of status symbols.
Top gemstones are sold at equally high amounts as well. Like in the case of rare rubies, especially Burmese stones of three carats and above will only be made available at specialty auction events with prices rivaling that of the pink diamonds.
As in the case of rare and truly real Kashmir sapphires, pegged at £100,000 per carat when they are available in the market at all. Tiffany and Christie auctions continue to push the mark higher for these stones whenever they appear. Even in the 2 – 10 carat range of brown and chocolate diamonds compete fiercely for the market share against emeralds and sapphires.
In the end, the ultimate winner is the consumer who has a unique piece of jewellery and the retailer who keeps a healthy mark up on the stones due to the lack of price list for direct comparison. Since coloured diamonds can’t be as exactly graded as expensive colourless diamonds, their value is more volatile.