Diamond is the hardest material on earth and the only gem composed entirely of carbon. A symbol of love, purity, innocence and eternity, diamonds have been popular since the 1400s, but the modern story of diamonds began in Africa during the nineteenth century when they became massively distributed. Diamonds are also available in fancy colors, like yellow and brown, which are rarer and more expensive. Fancy color diamonds come in most colors with the rarest being pink, red, orange, green, blue and purple. It is estimated that only one in 10,000 diamonds has a fancy color. Diamond is the birthstone for April and the gem for the 10th, 60th and 75th anniversaries.