Minerals in basaltic andesite include olivine, augite and plagioclase. Dacite consists mostly of plagioclase feldspar with biotite, hornblende, and pyroxene (augite and/or enstatite). Their commonest minerals are olivine, anorthite, hornblende, augite, biotite and leucite. Phenocrysts include augite, labradorite, olivine and plagioclase; additionally spinels are found in the rocks. They contain anorthoclase feldspars, biotite or greenish augite, much apatite and in some cases, olivine. It occurs with other zeolites, olivine, augite and nepheline. These rocks contain also iron oxides (usually titaniferous), apatite, sometimes sphene, augite, and olivine. Sanidine phenocrysts and augite (or enstatite) are found in some samples. Also dykes of augite syenite, picrite and 580 Ma tholeiite dolerite were intruded. Apatite, augite and opaque mineral inclusions are also found. Omphacite compositions are intermediate between calcium-rich augite and sodium-rich jadeite. The same rocks often contain similar aggregates of plumose skeleton crystals of augite. This leads to a miscibility gap between pigeonite and augite compositions. Pyroxenes rich in both the jadeite and augite endmembers are known as omphacite. Its space group (P2/n) is distinct from that of augite and jadeite (C2/c).