: 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).
1 Inorganic mercury is mercury combined with other chemical elements such as chlorine, sulfur or oxygen.  Organic mercury is mercury combined with carbon-containing compounds. A common form of organic mercury is methylmercury which is produced by microorganisms in water and soil, and which accumulates in fish.