Granite may have more alkali feldspar, whereas a granite derived from partial melting of metaigneous rocks may be richer in plagioclase. It is on this basis that the modern "alphabet" classification schemes are based. The letter-based Chappell & White classification system was proposed initially to divide granites into I-type (igneous source) granite and S-type (sedimentary sources). Both types are produced by partial melting of crustal rocks, either metaigneous rocks or metasedimentary rocks. M-type granite was later proposed to cover those granites that were clearly sourced from crystallized mafic magmas, generally sourced from the mantle. However, this proposal has been rejected by
Granite spiny lizard females have distinct yellow-tan transverse bands on their body and tail. Additionally, the male has deep-blue ventral patches on its chest and throat and femoral pores. The granite spiny lizard is a colorful species that can be observed perched atop boulders from considerable distance. This species is primarily associated with rocky hillsides and outcrops. They have been known to try to mate with other members of their sex. Granite spiny lizard The granite spiny lizard (Sceloporus orcutti) is a species of phrynosomatid lizard. The epithet, "orcutti", honors American naturalist Charles Russell Orcutt (1864–1929), who collected the type specimen in San