Period 6 element point of −38.83 °C and boiling point of 356.73 °C, mercury has one of the narrowest ranges of its liquid state of any metal. Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is mostly obtained by reduction from cinnabar. Cinnabar is highly toxic by ingestion or inhalation of the dust. Mercury poisoning can also result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury), inhalation of mercury vapor, or eating seafood contaminated with mercury. Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, and other
Cadmium telluride photovoltaics in Mexico and Sweden. In 1984 astrophysicists identified tellurium as the universe's most abundant element having an atomic number over 40. Certain undersea ridges are rich in tellurium. The manufacture of a CdTe cell includes a thin coating with cadmium chloride () to increase the cell's overall efficiency. Cadmium chloride is toxic, relatively expensive and highly soluble in water, posing a potential environmental threat during manufacture. In 2014 research discovered that abundant and harmless magnesium chloride () performs as well as cadmium chloride. This research may lead to cheaper and safer CdTe cells. By themselves, cadmium and tellurium are toxic