yellow sapphire is a gem of the corundum family and is a twin of ruby and blue sapphire. it is available in yellow, golden and orange colors. the highest quality is known to be of lemon-yellow color. the color in yellow sapphire is of iron and titanium.
amethyst is a violet variety of quartz. the name comes from a greek word, a refered to the belief that the stone protected its owner from drunkenness. the ancient greeks wore amethyst and carved drinking vessels from it in the belief that it would prevent intoxication.