Cinnabar is a very rare stone beings and has come to teach us of crystal alchemy. This stone being contains mercury and is not to be treated lightly in its handling. I have done some research and the consensus seems to be that it is safe to handle, providing you take precautions: ie, don't ingest, don't inhale the dust and wash hands after handling. I would add that it's best to keep this stone away from kids. Mindat has a health warning on their site if you want more information. I feel I should mention that there are many imitation versions of Cinnabar on the market and sometimes they are sold as authentic. I did get these stones from a reliable source, but even my source would not guarantee its authenticity. I trust it, but I always prefer to reveal everything I know about the stones. Having said that, mercury is another magical substance. Also known as quicksilver, it is the only metal that is liquid at room temperature. I have always loved its magical magnetic quality in how it comes together with separate drops of itself when they are close enough. In its solid form Cinnabar is red which connects it to Sulphur who is red when in liquid form.
Trust yourself with these stones as with all the stone beings. If you have any concerns or fears, please consider other stones.