| Astrophysics (Index) | About |
In astrophysical usage (e.g., planetary science, such as theories of planet formation) refractory material is material that becomes solid at a high temperature, thus becomes solid early during cooling. Other material that is slower to turn solid is called volatile material. The material in question can be a pure chemical element (refractory element or volatile element), or it can be a compound (refractory compound or volatile compound). A commonly-used threshold between the two is whether it turns solid above versus below 1300 K. For example, iron is moderately refractory and lithium is moderately volatile.
The more general meaning of refractory is "heat resistant". Also, astrophysics uses the term condensation and condensation temperature to refer to the material becoming solid as it cools whereas the word condensation typically refers to gas cooling and turning to liquid. I suspect this is because in the overall picture, an intervening liquid phase might be a mere detail.
The phrase refractory inclusion is often used for a piece of refractory material within a meteorite. The condensation temperatures of varying meteorite material is of interest regarding the conditions they underwent during their history.