Quartz

Gemstones in the quartz family include amethyst, aventurine, blue quartz, citrine, cat's eye, smoky and rose quartz. Clear quartz (sometimes streaked with white) looks like eternally frozen ice. When a particularly clean piece is mined and polished into a round ball, fortune tellers gaze into it to see your future. As a child, did you ever click two pieces of rock crystal together in the dark? If they are really quartz, you could see them light up with internal sparks! Don't try this with your quartz gemstones. Their hardness' vary so be sure and look for their individual names on Mohs scale of hardness.