Quartz var. Amethyst on Danburite

Several double terminated Amethyst Quartz crystals of delicate violet are clustered over and to one side of a colourless Danburite crystal from Charcas in Mun. de Charcas, San Luis Potosí, Mexico.  The double terminated crystals form back-to-back pyramids as there is no prism body.  The largest Amethyst crystals measure to about 7 mm on edge and the translucent to gemmy Danburite, a calcium-boron silicate, is 2 cm tall.  This lovely large thumbnail is mounted vertically on a square acrylic base.