Gruesome California Crime Stories That May Play A Part In âTrue Detectiveâ Season 2. Nic Pizzolatto isnât letting us into his warped, deviant mind when it comes to salient plot points surrounding the second season of the highly-acclaimed HBO anthology series, True Detective, but he has dropped a few hints.
Rhyolite: Fine-Grained Felsic Rock Most rhyolites are light gray to pinkish in color, but red or even black rhyolites are not rare. Most rhyolites are porphyritic and are identified by the quartz phenocrysts and white to salmon K-feldspar phenocrysts. The groundmass is aphanitic or even glassy.
Igneous rocks are classified according to their silica content. Rocks that contain lots of silica are usually light-colored. Most important minerals are feldspars and quartz. These rocks are referred to as felsic rocks (feldspar + silica). Common felsic rocks are granite and rhyolite.