Chalcedonies include many types of cryptocrystalline quartz gems and feature a number of different colors. Geologists can tell a chalcedony from the arrangement and structure of its crystals.

You can find topaz, opals, amethysts, and more — there are over 40 different gemstones possible in every scoop. The larger the container, the more jewels you'll uncover. You can sift your own ...