The Gubelin Gem Lab criteria for Golconda diamonds do not mention anything about the blue afterglow in direct sunlight observed in many Golconda diamo...

It is said that the baroque drop-shaped pearl is the largest natural pearl ever offered for sale at Christie's Dubai. The pearl is also said to be amo...

What oyster species could possibly have produced this large pearl ?

What are the largest pearls in each of the categories you have mentioned ?

To what extent do these different shapes occur in nature ?

How does the CIBJO Pearl Book define Conch pearl, Quahog pearl and Melo Melo pearl ?

Is there an international body that sets up the standards and guidelines for the natural and cultured pearl industry ?