Thesapphire It's a variety ofcorundum, which chemically it isaluminum oxide Strongly allochromatic. It has hardness 9 on theMohs scale.
Color: BLUE Intense with oval cut transparency
Technical characteristics of the ring
18kt white gold
Brilliant cut diamonds CARATO 0.31 Color F Purity VS
Sapphire cut "oval" 1.34