Ruby is the birthstone for July and has a hardness of 9 on the Mohs scale, second only to diamonds. It is from the same gem family as sapphires which is called corundum, but it is the presence of chromium that creates the red only found in rubies. They have the highest per-carat price of any coloured stone because of their rarity, hardness, colour, durability, and brilliance.
They are also one of the most historically significant coloured stones and have always associated with the most intense emotions such as passion, romance, and power. Rubies are a traditional gift for those celebrating their 15th or 40th anniversary.