Granite and feldspar. The term "granitic" means granite-like and is applied to granite and a group of intrusive igneous rocks with similar textures and slight variations in composition and origin. These rocks mainly consist of feldspar, quartz, mica, and amphibole minerals, which form an interlocking, somewhat equigranular matrix of feldspar and quartz with scattered darker biotite mica and amphibole (often hornblende) peppering the lighter color minerals. Occasionally some individual crystals (phenocrysts) are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic texture is known as a granite porphyry. Granitoid is a
What Is and What Should Never Be What Is and What Should Never Be "What Is and What Should Never Be" is a song by English rock band Led Zeppelin. It was written by Jimmy Page and Robert Plant and was included as the second track on "Led Zeppelin II" (1969). "What is and What Should Never Be" was one of the first songs on which Page used his soon-to-become trademark Gibson Les Paul for recording. The production makes liberal use of stereo as the guitars pan back and forth between channels. Robert Plant's vocals were phased during the verses. Record producer Rick Rubin has remarked, "The