Huang Longyu, also known as chalcedony, has the same composition as agate. Because of its many producing areas and large output, it does not have long-term investment value at present. But in recent years, this variety has been seriously hyped, so the price has risen rapidly. Huang Longyu, also known as the Dragon and Yellowstone. Location: Longjiang River, Xiaoheishan Nature Reserve, Longling County, Baoshan City, Yunnan Province. It was discovered and renamed in Yunnan in 2004. The main color of Huang Longyu is yellow, and there are also sheep fat white, bluish white, red, black, gray and green. Known as "yellow as gold, red as blood, green as jade, Bai Rubing as black as ink". Specifically: yellow is yellow with different shades such as golden yellow, honey yellow, egg yolk, chicken oil yellow, orange yellow and loquat yellow; The red ones are light red such as chicken blood red, cinnabar red, pig liver red and rose red; White has snow white, ice white and so on. It was named Huang Longyu by Yunnan Ornamental Stone Association. The main component is silicon dioxide, but it is not a single crystal, but a polycrystalline complex similar to chalcedony and agate, with a hardness of 6.5-7. In cryptocrystalline texture, there are similar varieties of yellow wax stones, which are produced in Yunnan, Jiangxi, Inner Mongolia and other places. Self-identification skills: the knife doesn't move, but the crystal can.