HgS is the chemical formula for mercuric sulfide, a compound of sulfur and mercury, which can be used as an herbal medicine inside Chinese medicine, i.e. cinnabar. Cinnabar is usually harvested by digging out the ore, selecting the pure ones, and using a magnet to suck out the iron impurities and wash away the stones and sediment. In traditional Chinese medicine, cinnabar has the effects of calming the heart and tranquilizing the mind, clearing heat and detoxifying toxins, and is usually used to treat insomnia, convulsions and seizures, pediatric convulsions (a pediatric disease that manifests itself mainly in dizziness, convulsions and seizures), sore throat, and mouth and tongue sores. Cinnabar is a toxic herb, which can easily cause toxic substances to accumulate in the body, so it should be avoided in large quantities and for a long time. Pregnant women and those with liver or kidney insufficiency should avoid using Cinnabar. The use of cinnabar needs to be rationalized under the guidance of a doctor, do not arbitrarily use on your own.