Multiple choice general knowledge science & technology The red mineral cinnabar is the chief source of: Clay Cinnamon Mercury Ethanol Reveal answer Fill a bubble to check yourself C Correct answer Explanation Cinnabar is mercury(II) sulfide (HgS), the primary ore of mercury. Clay is a sedimentary material used in ceramics, cinnamon is a spice derived from tree bark, and ethanol is an alcohol compound - none are mineral sources of mercury.