Usually minute amount of liquid and/or gas trapped in a crystal during crystallization or recrystallization. There are two ways in which solid phases in fluid inclusions may originate. (a) One or more mineral grains may be trapped along with the fluid phase(s) during formation of the fluid inclusion. (b) One or more solid phases may form in a fluid inclusion after its initial formation as a result either of a reaction between the fluid and the host mineral, or by precipitation from the fluid upon cooling (in which case the solids are known as daughter minerals). The temperature and composition of the fluid from which the enclosing mineral originated can be estimated from studies of such inclusions.
Subjects: Earth Sciences and Geography.