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
Wave Rock land surface. This process formed underground "domes" of solid granite bedrock surrounded by deeply weathered, relatively loose, and disaggregated granite. Following separation of Australia and Antarctica and accompanying tilting of what became southwestern Australia, periodic erosion of the deeply weathered granite, which underlaid the surrounding land surface, exposed these buried solid bedrock domes over time as Hyden Rock. Wave Rock is a spectacular example of what geomorphologists call a "flared slope". A flared slope is a concave-upward or -inward bedrock surface that is typically found around the base of inselbergs, bornhardts, and granitic boulders and also on their higher slopes.