麻粒岩又名粒变岩，是一种变质岩，变质程度较深，颗粒较粗，具有粒状变晶结构，有不明显的片麻状结构或块状构造，其特点是没有含水矿物，如云母、角闪石等，常含有斜长石、铁铝榴石或辉石。

最常见的麻粒岩有：

根据原岩和矿物组合可分为: •暗色麻粒岩 mafic minerals>35%, pl>An30, basaltic, 原岩；结构；命名(石榴二辉斜长麻粒岩，紫苏辉石 斜长麻粒岩)；形成条件 •浅色麻粒岩 mafic minerals<35%, pl<An35, qz occurs, antiperthite is common, Al-rich mineral sometimes occur, 原岩；结构；命名(二辉斜长麻粒岩，紫苏黑云二长 麻粒岩)；形成条件 •紫苏花岗岩 qz>20%, mafic minerals<10%, kf common 成因？ 依据压力大小，可分出： • 低压麻粒岩(<0.7~0.8GPa) — opx+pl+cd+qz±cpx ±kf (pelitic protolith), no gt; cpx+opx+pl for basaltic protolith • 中压麻粒岩(> 0.7~0.8GPa) — opx+cpx+pl+gt, no cd, • 高压麻粒岩(>1.2~1.3 GPa)—cpx+pl+gt±qz; gt+cor +sap±ant±phl±ru; gt+pl+qz+cpx+ky+ru, no bt

Granulites are a class of high-grade metamorphic rocks of the granulite facies that have experienced high-temperature and moderate-pressure metamorphism. They are medium to coarse–grained and mainly composed of feldspars sometimes associated with quartz and anhydrous ferromagnesian minerals, with granoblastic texture and gneissose to massive structure. They are of particular interest to geologists because many granulites represent samples of the deep continental crust. Some granulites experienced decompression from deep in the Earth to shallower crustal levels at high temperature; others cooled while remaining at depth in the Earth.