Two-phase inclusions

Two-phase inclusions are cavities inside crystals filled with two different phases. Most common examples are liquid-vapor inclusions, but other combinations are also possible, for example, two immiscible liquids such as water and liquid CO2 or water and liquid hydrocarbons (petroleum) can also be found.

It’s important to emphasize that the majority of two-phase inclusions, as well as tree- and multi-phase inclusions were trapped by growing crystal as a single phase fluid that later separated in two or more phases due to cooling of the sample to room temperature. Also, solid phase can be precipitated from the solution, forming a crystal of so called “daughter mineral” inside the cavity. In general, all phases separated from primary homogeneous fluid that have been trapped during crystal growth are called “daughter phases”, which include liquid, solid and gaseous phases formed inside inclusion cavity due to cooling to observation conditions. When fluid inclusion is heated, all daughter phases will gradually disappear to form homogeneous fluid again.

In the following sections some examples of two-phase inclusions of different types are described.