EPIDOTE • FREE-TRANSLATOR.COM • Definition of Epidote

... minerals are omitted which, even if they are of common occurrence, are more to be regarded as accessory than as essential components of the rocks in which they are found. (For analyses of these minerals see the Mineralogies of Dana and Bristow.) Such are, for example, Garnet, Epidote, Tourmaline, Idocrase, Andalusite, Scapolite, the various Zeolites, and several other silicates of somewhat rarer occurrence. Magnetite, Titanoferrite, and Iron-pyrites also occur as normal constituents of various igneous rocks, although ...

— The Student's Elements of Geology • Sir Charles Lyell