In-between the end members minerals as a combination of both anchor members exist. Sometimes, these intermediary minerals are given names. An example of this is a mineral series known as the Olivine group . In the Olivine group, the two end members are Forsterite and Fayalite . Mg 2 SiO 4 Fayalite Fe 2 SiO 4 Another member of the Olivine group is Chrysolite .
Chrysolite is an intermediary member, so it has a varying amount of magnesium and iron.
However, in certain mineral series, intermediary members are given names based on defined percentages of the elements they contain. Some mineral series, such as the Spinel series , contain more than two end members. This means there can be many different combinations of intermediary members. In a few complex mineral series, such as Garnet , more than one element may be replaced by another. In large series such as Garnet, nearly hundreds of possible intermediary combinations can exist.