Associated minerals include garnets, vesuvianite, diopside, tremolite, epidote, plagioclase feldspar, pyroxene and calcite. Associated minerals include vesuvianite, chlorite, epidote, spinel, calcite, dolomite and magnetite. Gangue minerals included calcite, quartz, epidote, chlorite, and various zeolites. The major accessory minerals of TTG rocks include biotite, amphiboles (e.g. hornblende), epidote, and zircon. Less common minerals can include biotite, garnet, actinolite, epidote, chalcedony, prehnite, and wodginite. Associated minerals include prehnite, danburite, babingtonite, epidote, native copper, calcite, quartz and zeolites. Alteration has formed chlorite, epidote and sericite. Associate minerals include epidote, titanite, glaucophane, garnet and quartz. The rock is veined with calcite, light green epidote, and deep red hematite. The minerals that accompany them are calcite, epidote, vesuvianite, garnet, wollastonite, diopside and amphibole. Epidotization is the alteration process in which plagioclase feldspars convert into the epidote group minerals. Hornblende alters easily to chlorite and epidote. Mineral deposits such as haematite, calcite and epidote can be seen within these features. Alteration of the erupted rocks has given rise to clay, chlorite, epidote and illite. A rock composed of quartz and epidote is known as epidosite.