Sapphires are the second hardest mineral on Earth, so they are fantastically durable, 9 on the Mohs scale. They also come in a vast range of colours. Most commonly known in blue, at Alex Monroe we are especially fond of green sapphires. They also come in vibrant yellows, oranges, purples and pinks. Peach sapphires – known as Padparadscha are some of the most beautiful and rare.