Update from wikipedia:

The Goldschmidt classification, developed by Victor Goldschmidt, is a geochemical classification which groups the chemical elements according to their preferred host phases into lithophile (rock-loving), siderophile (iron-loving), chalcophile (ore-loving or chalcogen-loving), and atmophile (gas-loving) or volatile (the element, or a compound in which it occurs, is liquid or gaseous at ambient surface conditions).
Some elements have affinities to more than one phase.
Lithophile elements are those that remain on or close to the surface because they combine readily with oxygen, forming compounds that do not sink into the core.
Siderophile (from sideron, "iron", and philia, "love") elements are the high-density transition metals which tend to sink into the core because they dissolve readily in iron either as solid solutions or in the molten state.
Chalcophile elements are those that remain on or close to the surface because they combine readily with sulfur and/or some other chalcogen other than oxygen, forming compounds which do not sink into the core.
Atmophile elements (also called "volatile elements") are defined as those that remain mostly on or above the surface because they are, or occur in, liquids and/or gases at temperatures and pressures found on the surface.
See also: http://ruby.colorado.edu/~smyth/G30103.html