Turquoise Cabochon TURQUOISE Oval 40x30mm This is medium height domed cabochon with flat back. Colour and appearance may vary as these are created from natural material that has intrinsic variation. The illustration may be taken as a guide. Turquoise is birthstone for December. Popularised by it's use in Egypt about 5000 years ago. Said to guarantee the fidelity of those in love.