Mumbai (Maharashtra) [India], September 16 (ANI/NewsVoir): Gemfields is delighted to announce the final instalment in the trilogy of books dedicated to the celebration of coloured gemstones, published by Thames & Hudson in association with Violette Editions. The much-anticipated release of Sapphire - which follows on from Emerald and Ruby - will complete a literary trifecta dedicated to the most revered coloured gemstones: emeralds, rubies and sapphires, often called "the big three".