Descriptive of two minerals with the same crystal structure but different end-member compositions which may show partial or complete crystal miscibility (solid solution) between them. One mineral may belong to more than one isomorphous series; e.g., the garnet grossular forms a series with andradite, with hibschite and katoite, and with uvarovite. There are many isomorphous series among minerals; e.g., plagioclase feldspars, monoclinic pyroxenes, and the spinel and garnet groups. Compare: solid solution