Precious stones

Precious stones: sapphire, ruby, emerald

Only three stones officially bear the name of precious stones alongside the diamond: sapphire, ruby and emerald. All the others, however beautiful, are fine stones. For these three stones, value is not read as it is for a diamond: it is the intensity and purity of the colour, the geographical origin and whether or not the stone has been treated that make the price difference, sometimes by a factor of ten for a comparable apparent colour.

What drives the value

Treatments and transparency

The vast majority of coloured stones on the market have been treated, most often by heating for sapphire and ruby, and by oiling for emerald, whose natural inclusions, the jardin, are inherent to the stone. These practices are accepted when they are disclosed. A certified unheated stone trades well above a treated stone of equivalent colour. We state what the gemmological report establishes, without extrapolating.

Frequently asked questions

Why does the origin change the price so much?

Because some historic mines, now exhausted or closed, produced colours that are not found anywhere else. Only a laboratory can give an opinion on an origin.

Is an oiled emerald a defect?

No, it is the norm for this stone. What matters is the nature and extent of the oiling, stated on the report.

Do you have the stones certified?

Important stones are sold with their laboratory report when one exists. We can also have a stone analysed on request.