: to make (something) more attractive usually by putting something on it.
There are several types of mercury. They include metallic mercury, and both inorganic and organic mercury compounds. Many of these forms are found in our environment, however, the most common natural forms include metallic mercury, mercury sulfide, mercuric chloride, and methylmercury (http://www.atsdr.cdc.gov/toxprofiles/tp46.html).
Inorganic mercury compounds or mercury salts, more commonly found in nature, include mercuric sulphide (HgS), mercuric oxide (HgO) and mercuric chloride (HgCl2). Most of these are white powders or crystals, except for mercuric sulphide which is red and turns black after exposure to light.