De Beers Reduces Rough Prices – Too Little?
De Beers reduces rough prices at May sight, undisclosed treated diamonds submitted to GIA, and Sotheby’s and Christie’s sales break auction records − again.
The “Type” Classification System of Diamonds and Its Importance in Gemmology
Knowledge of type allows gemmologists to better evaluate if a diamond might be treated or synthetic, and whether it should be sent to a laboratory for testing.
Characterisation and Grading of Natural-Colour Yellow Diamonds
A large number of natural-colour yellow diamonds are analysed using grading and appearance aspects among other characteristics to clarify the differences between them and the light yellow diamonds associated with GIA's D-to-Z colour grading scale.
An Important Exhibition of Seven Rare Gem Diamonds
The stories behind seven strikingly beautiful rare natural diamonds, united in an exhibit at the Smithsonian, are told here.
Characterisation and Grading of Natural-Colour Pink Diamonds
Known for their great beauty and rarity, pink diamonds have long been sought after by jewellers, collectors and consumers.
Grading the Hope Diamond
One of the most popular exhibits at the Smithsonian Institution, the stunning Fancy Dark greyish blue Hope diamond was formally graded by GIA’s gem laboratory.