Enamel colours are built up layer by layer, fired in order of hardness due to their varying ... rubies, emeralds, topaz, pearls, and semiprecious gems. On both sides of the street, lapidaries ...

Skoltech researchers have presented a new simple physical model for predicting the hardness of materials based on information about the shear modulus and equations of the state of crystal structures.

Kate paired her structured emerald green-based outfit with the dazzling 'Daystar Blue Topaz Earrings' from British Fine Jewellery label Robinson Pelham, retailing on the brand's website at £5,995.

In the snap, she modeled her signature “glazed” nails and hand tattoos, as well as a custom gold ring adorned with two birthstones: her own, a teardrop-shaped topaz, and her newborn son Jack ...

The Princess unveiled a brand new pair of topaz and diamond earrings. Picture: Samir Hussein/WireImage Kate wore a festive green coat by Sarah Burton for Alexander McQueen for the appearance and ...

Stones are ranked according to the Mohs hardness scale, with diamonds scoring a perfect 10. (The next hardest stone, ruby, is four times less durable than diamond—but still comes in at a 9.) A stone ...