In planetary science, any material that has a relatively high equilibrium condensation temperature is called refractory. The opposite of refractory is volatile. The refractory group includes elements and compounds like metals and

silicates In chemistry, a silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name i ...

(commonly termed rocks) which make up the bulk of the mass of the

terrestrial planet A terrestrial planet, telluric planet, or rocky planet, is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets accepted by the IAU are the inner planets closest to the Sun: Mercury, ...

s and asteroids in the inner belt. A fraction of the mass of other

asteroids An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

, giant planets, their moons and

trans-Neptunian object A trans-Neptunian object (TNO), also written transneptunian object, is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune, which has a semi-major axis of 30.1 astronomical units (au). Typically ...

s is also made of refractory materials.

Classification

The elements can be divided into several categories: The condensation temperatures are the temperatures at which 50% of the element will be in the form of a solid (rock) under a pressure of 10⁻⁴ bar. However, slightly different groups and temperature ranges are used sometimes. Refractory material are also often divided into refractory lithophile elements and refractory

siderophile elements The Goldschmidt classification, developed by Victor Goldschmidt (1888–1947), is a geochemical classification which groups the chemical elements within the Earth according to their preferred host phases into lithophile ( rock-loving), siderophil ...

References

Planetary geology Petrology Volcanology Astrobiology Origins Prebiotic chemistry {{astrobiology-stub