This is generally a dark-colored rock. Garnet hornfels has reddish patches and crystals of garnet set into the matrix. It also contains quartz, mica, and feldspar and metamorphic minerals such as cordierite and andalusite.

TEXTURE This is a fine- to medium -grained rock with a tough, splintery texture. The distinct garnet crystals give garnet hornfels a porphyroblastic texture.

ORIGIN Develops in the contact aureoles of large igneous intrusions. These can be formed of granite, syenite, and gabbro.

Group: METAMORPHIC

Grain size: Fine

Classification: Contact

Pressure: Low

Temperature: High

Structure: Crystalline