However , in the United States , a minimum color saturation must be met to be called a ruby ; otherwise , the stone will be called a pink sapphire .
Generally , gemstone - quality corundum in all shades of red , including pink , are called rubies .
In the United States , a minimum color saturation must be met to be called a ruby ; otherwise , the stone will be called a pink sapphire .
Generally , gemstone - quality corundum in all shades of red , including pink , are called rubies .