Mercury can freeze.
Mercury’s freezing temperature has been recorded and definitively discovered. Its freezing point is actually capable of being hit naturally on Earth, although this temperature is only found in the more extreme climate areas on the planet.
Mercury (commonly referred to by the symbol “Hg”) is the only common metal on the periodic table found naturally in its liquid state. This could be considered surprising in the grand scheme of existence considering that mercury’s liquid range is actually the lowest of any other element. Mercury is considered a poor conductor of heat, making it even more unusual for metals. It is, however, a fair conductor of electricity. [“Why Is Mercury a Liquid at STP?” General Chemistry Online]
Mercury reaches the solid state at -38.72 degrees Celsius making it theoretically possible for mercury to freeze in places with extreme temperatures. As an example, the lowest recorded temperature on Earth was measured at -88 degrees Celsius in Antarctica. [“What Are the Highest and Lowest Temperatures on Earth?” California Institute of Technology]
Mercury as a Solid
Solid mercury looks relatively similar in color to the liquid variety. Due to its color, we commonly call the liquid “quick silver.” This same coloration is found in the metal when converted to a solid. In addition a number of different amalgamates can be included into the mixture to actually allow the compound to be solid at room temperature. The silvers fillings used by dentists in the past, called an amalgam filling, are a perfect example of this concept. [“Why is mercury liquid at room temperature?” MIT Engineering]
“Why Is Mercury a Liquid at STP?” General Chemistry Online: FAQ: Introduction to Inorganic Chemistry:. N.p., n.d. Web. 02 Jan. 2013.
“What Are the Highest and Lowest Temperatures on Earth?” California Institute of Technology–Ask an Astronomer for KIDS! N.p., n.d. Web. 02 Jan. 2013. http://coolcosmos.ipac.caltech.edu/cosmic_kids/AskKids/earthtemp.shtml
“Mercury – Hg.” Mercury (Hg). N.p., n.d. Web. 02 Jan. 2013.http://www.lenntech.com/periodic/elements/hg.htm
“Why is mercury liquid at room temperature? • Ask an Engineer at MIT Engineering.” MIT Engineering. N.p., n.d. Web. 8 Jan. 2013. <http://engineering.mit.edu/live/news/2304-why-is-mercury-liquid-at-room-temperature>.