Volatile element
A volatile element condenses only at low temperatures and is easily lost when rock is heated, such as sodium, zinc, lead or water.
A volatile element condenses into solids only at fairly low temperatures and evaporates easily when heated. Moderately volatile elements include sodium, potassium, zinc and lead; highly volatile ones include mercury, thallium, the halogens and the ingredients of ice such as carbon, nitrogen and hydrogen.
Meteorites vary greatly in their volatile content. CI chondrites keep almost the full solar share, while eucrites, angrites and the Moon are strongly depleted, showing that their material was heated or that they formed where volatiles had not condensed. Ordinary chondrites sit in between.
The pattern of volatile loss is a big clue to planet building. Earth is depleted in volatiles compared with CI chondrites, yet it has oceans, which raises the question of when and from where its water and other volatiles arrived. Isotopes of volatile elements such as zinc and potassium help researchers trace whether material was lost by evaporation during impacts or never gathered in the first place.
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