- For other uses, see class F.
Class F silicate, in planetary classification, is a type of planet. These rocky, metallic worlds have also been classified as class G geocrystalline planets on other scales, and are possessed of an oxidizing atmosphere. Lifeforms have a difficult time taking hold on these dry worlds. (ST references: Star Trek Maps, The Worlds of the Federation)
- The source reference only called this a "class F planet", but another source calls planets of a different type by the same name, leading to the term "silicate" to be used as a descriptor to disambiguate the two terms. In the conflicted source, ST reference: Star Charts, planets similar to these worlds are called "class G geocrystalline planets".