Cinnabar is a naturally occurring, bright red mineral. It is made mainly of mercury and sulfur, in a compound called mercury sulfide (HgS). Historically, people ground it into a red pigment called vermilion and mined it as an important source of mercury.
Is cinnabar poisonous?
It can be hazardous, but risk depends on the form and exposure. Mercury in cinnabar is bound to sulfur and is generally less readily absorbed than the mercury vapor released by some other mercury compounds. However, cinnabar is not safe to eat, inhale as dust, or handle carelessly. Grinding, heating, or otherwise processing it can create dangerous dust or release toxic mercury vapor.
How to stay safe
- Do not taste it, grind it, or heat it.
- Avoid breathing dust and wash your hands after accidental contact.
- Keep mineral specimens away from children and pets; store them securely.
- If a specimen is damaged or you think you may have inhaled dust, contact a health professional or local poison-control service for advice.
So, cinnabar is a striking mineral with an important history, but it should be treated as a potentially toxic material—not as an ordinary rock or craft pigment.