Friendship, love and loyalty are represented by this historic celtic design. A Blue Topaz claddagh ring with your birthstone or favorite color makes it even more significant. The birthstone of December, the tranquil azure color of a blue topaz ring can evoke thoughts of warm Caribbean seas on a cold winter day. Sapphire is the birthstone of September, and pink sapphire is a very popular gemstone in jewelry today. The bright and happy color of a pink sapphire ring is both playful and trendy.