Padparadscha Sapphire & heat treatment
Stephen Kennedy
Nitrogen aggregates in yellow HPHT and CVD synthetic diamonds
Yuri Shelementyev, Galina Kriulina, Olga Yarapova, Viktor Vins, and Alexander Stolyarevich
Study of “amethysts” from the French Crown Jewels
Stefanos Karampelas, Eloïse Gaillou, Annabelle Herreweghe, Ugo Hennebois, Farida Maouche, Romain Bo