Gallium is a metal with a very low melting point. In fact it will melt in your hand after a few minutes. Once it is liquified, it is an interestingly dense liquid, similar to mercury (except gallium is non-toxic!) This vial contains 15g of this interesting element.
Non-toxic, but we wouldn't eat it. Like water, gallium expands when frozen, so don't store it in glass.
Gallium is a chemical element with symbol Ga and atomic number 31. It is in group 13 of the periodic table, and thus has similarities to the other metals of the group, aluminium, indium, and thallium. Gallium does not occur as a free element in nature, but as gallium(III) compounds in trace amounts in zinc ores and in bauxite. Elemental gallium is a soft, silvery blue metal at standard temperature and pressure, a brittle solid at low temperatures, and a liquid at temperatures greater than 29.76 °C (85.57 °F) (above room temperature, but below the normal human body temperature of 98.6 °F (37.0 °C), hence, the metal will melt in a person's hands).