<P> A ruby is a pink to blood - red colored gemstone , a variety of the mineral corundum ( aluminium oxide ) . Other varieties of gem - quality corundum are called sapphires . Ruby is one of the traditional cardinal gems , together with amethyst , sapphire , emerald , and diamond . The word ruby comes from ruber , Latin for red . The color of a ruby is due to the element chromium . </P>
<P> A ruby is a pink to blood - red colored gemstone , a variety of the mineral corundum ( aluminium oxide ) . Other varieties of gem - quality corundum are called sapphires . Ruby is one of the traditional cardinal gems , together with amethyst , sapphire , emerald , and diamond . The word ruby comes from ruber , Latin for red . The color of a ruby is due to the element chromium . </P>
red colour of ruby crystal is due to
red colour of ruby crystal is due to
the element chromium
the element chromium