Emeralds are the most highly valued gemstone (apart from diamonds) and are the rarest gemstone available. They are considered the gem of royalty and romance. Emeralds are known for their deep green color and natural inclusions that make each one distinct. Emeralds are Mays birthstone and gifted traditionally on the 55th milestone anniversary. The scientific name for Emerald is natural beryl. The green coloring is attributed to trace elements of chromium and vanadium. Unlike many other precious gemstones, emeralds are much softer. They rank 7.5 on the Mohs scale (diamonds are 10).