Colorado is certainly known for mining gold, silver, and other minerals, but many people don't realize that Colorado is also the source of many beautiful gemstones. In fact, Colorado even has a state gemstone, aquamarine. According to the Colorado Geological Survey, more than 30 different gemstone varieties are found in Colorado. Some of these include agate, garnet, topaz, tourmaline, quartz, amethyst, turquoise, lapis lazuli, and peridot. Diamonds are also found in Colorado; in fact, the largest faceted diamond ever produced in the U.S., weighing in at an amazing 16.87 carats, was found right here in Colorado. You can learn all about Colorado gemstones, including how and where they are found, by visiting the Gemstones page on the Colorado Geological Survey's website.