Four famous gemstones known for their beauty and rarity are: Diamond: Diamonds are renowned for their brilliance and are one of the most sought-after gemstones in the world. They are prized for their exceptional hardness, fire, and scintillation. Ruby: Rubies are prized for their deep red colour and are considered one of the most valuable gemstones. They symbolize passion and are often associated with royalty. Sapphire: Sapphires come in various colours, but blue is the most well-known. They are prized for their rich blue hue and durability. Sapphires are also associated with wisdom and royalty. Emerald: Emeralds are known for their vivid green colour. They are valued for their beauty and rarity. Emeralds have been treasured throughout history and are often associated with growth, rebirth, and love.