Page "Gemstone" Paragraph 13

Aside from the diamond, the ruby, sapphire, emerald, pearl ( not, strictly speaking, a gemstone ) and opal have also been considered to be precious.

Up to the discoveries of bulk amethyst in Brazil in the 19th century, amethyst was considered a precious stone as well, going back to ancient Greece.

Even in the last century certain stones such as aquamarine, peridot and cat's eye have been popular and hence been regarded as precious.