The Logan Sapphire Flawless sapphire is the second largest known one in the world, a staggering carats. The cushion-cut stone is one of the world's largest and most famous sapphires, set in a brooch surrounded by 20 round-cut diamonds weighing 16 carats.
A Chalcedony, Sapphire and Diamond ring, Asprey, centering a blue Chalcedony cabochon measuring approximately x x surrounded by round brilliant-cut Diamonds, further accentuated by oval and circular-cut blue Sapphires;
SAPPHIRE AND DIAMOND RING, OSCAR HEYMAN & BROTHERS. Claw-set with a cushion-shaped sapphire weighing carats, within a line of pear-shaped diamonds, further decorated with brilliant-cut stones, mounted in yellow gold and platinum
Extremely rare and valuable emerald in an Art Deco ring. Made by Cartier Paris, in The emerald weighs carats and is surrounded by carats of diamonds. The ring will be auctioned by Christies on January 2014
Smithsonian Canary Diamond A spectacular, Sparkling and Rare Yellow "Canary" Diamond, mounted in a Ring is part of the Gem and Mineral Collection of the Smithsonian's National Museum of Natural History.