Monticellite is a rare mineral that is mainly found in volcanic rocks, such as those that make up the Earth's mantle. Although it has a unique name, there are a few synonyms that can be used to refer to this mineral. One such synonym is the name "calcium magnesium olivine", which describes the fact that monticellite is a type of olivine mineral that contains both calcium and magnesium. Another synonym for monticellite is "periclase-rich melilite", which refers to the fact that monticellite often occurs with other minerals such as periclase and melilite. While these synonyms are not as commonly used as the term monticellite, they provide a useful way to describe this important mineral.