Amethyst is the purple variety of quartz and the most valued member of the quartz family. It must be purple to be amethyst, but it can display a range of shades including deep purple, light lilac, lavender and mauve.
Azurite is a blue copper mineral with the chemical formula It forms monoclinic crystals. Azurite weathers into malachite. Azurite is used as a pigment, in jewelry, and as a decorative stone. This stone is called "Velvet Beauty" from Bisbee, Arizona.