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
Exfoliating granite Nevada Mountain Range. Engineers began construction on the dam is 1928 and placed the structure between two granite domes. In August 2014, the granite developed exfoliating joints and began to leak. The process was captured on video and is one of a couple ever to be caught on film. The lake was completely drained and the cost of reconstruction nine-hundred thousand dollars. In June 2016, the granite rock had to be closed off for a second time because of the continued exfoliation. Grove Karl Gilbert is considered one of the most influential geologists of his generation. He was the only