A certificate from a recognised laboratory is essential for any important stone. But it only answers some of the questions that decide what a stone is worth.
What a certificate tells you
A laboratory certificate identifies the stone, gives its weight and measurements, and states whether it has been treated. For coloured stones, it often gives an opinion on geographic origin. This is the basis of any serious purchase. But a certificate never gives a price.
What it does not tell you
A certificate does not tell you whether a stone is beautiful. It cannot show how the colour looks in daylight, how evenly it is spread, how lively the stone is, or how well it was cut. Two rubies with almost identical certificates can differ greatly in price, simply because one is more beautiful than the other.
Specialists at the major auction houses say the same thing: a certificate confirms what a stone is, but judging its quality and value takes an experienced eye.
How we work
- We examine every stone ourselves with gemmological instruments.
- We choose the right laboratory for each stone and go through the certificate with you.
- We judge colour, cut and beauty, and because we trade stones every day, we know the market and give you an accurate estimate of value.