Why are Diamonds valuable???

Diamonds are most admired stones on Earth and has been one of the most sought after jewels for thousands of years. Diamonds as formed millions of years ago are said to be rare because some original quality diamonds have to survive the difficult journey from the core of earth to reach earth's surface.
Until the 15th century, kings were the only ones allowed to wear diamonds as it was considered to be a symbol of strength and courage. Those who wore diamonds where thought to be invincible. Over the years the diamond has become better known as the ultimate gift of love. Since its discovery diamonds have always been coupled with the thoughts of romance and legend. The word diamond originates from a Greek word which means unconquerable. This suggests the eternal nature of love, further going along with the Greek philosophy that the fiery brilliance of the diamond reflects the undying flame of love.