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.
The two best-known igneous rock types are basalt and granite, which have distinctly different compositions and textures. Basalt is the dark, fine-grained stuff of many lava flows and magma intrusions. Its dark minerals are rich in magnesium (Mg) and iron (Fe), hence basalt is called a mafic rock.ranite is the light, coarse-grained rock formed at depth and exposed after deep erosion. It is rich in feldspar and quartz (silica) and hence is called a felsic rock. So granite is felsic and plutonic. Basalt and granite account for the great majority of igneous rocks.