NATIVE MERCURY

Chemistry: Hg, Elemental Mercury
Class: Elements
Group: Gold
Uses: Minor ore of mercury, electrical switches, thermometers
Specimens

Mercury is unique, as it is the only metal that is liquid at room temperature, having a melting point of -40 C, and a boiling point of 357 C. This silvery liquid metal is very dense, yet has a high surface tension that causes is to form tiny little perfect spheres in the pores of the rocks it is found in. Many mineralogical characteristics simply do not apply to a liquid: there is no "hardness", since it cannot be scratched (nor can it scratch); there is no crystal structure, no fracture, no cleavage, no streak; all of course, at room temperatures. When frozen, mercury forms crystals in the rhombohedral system at low pressure, and in the tetragonal system at high pressure.

PHYSICAL CHARACTERISTICS:

Color is bright silvery metalic.
Luster is metallic.
Transparency is opaque.
Crystal System does not apply
Crystal Habits spherical droplets, or pools of mercury liquid.
Cleavage does not apply
Fracture does not apply
Streak does not apply
Hardness does not apply
Specific Gravity is 13.5+ (very dense)
Associated Minerals are cinnabar, calomel, and other secondary mercury minerals.
Other Characteristics: Mercury is a liquid! It also expans at a constant rate with a rise in temperature.
Notable Occurrences include Almaden, Spain; Idrija, former Yugoslavia; Italy; California, Oregon, Texas, and Arkansas, USA.
Best Field Indicators its a liquid!