The metamorphic rock texture in which mineral grains are arranged in planes or bands is:

The metamorphic rock texture in which mineral grains are arranged in planes or bands is:

• A. Foliation
• B. Cleavage
• C. Fracture
• D. Luster

Answer: (A)

Foliation is the metamorphic rock texture where mineral grains align in parallel planes or bands. This happens when rocks are subjected to directed pressure during metamorphism, causing flat or platy minerals (like mica) to realign perpendicular to the compression and form a layered fabric. The resulting rocks—slate, phyllite, schist, and gneiss—show this planar texture. It’s different from cleavage, which is a rock’s tendency to break along smooth planes, not a true reorientation of minerals. Luster and fracture describe surface shine and how a rock breaks, not the internal planar arrangement that defines foliation.

Foliation is the metamorphic rock texture where mineral grains align in parallel planes or bands. This happens when rocks are subjected to directed pressure during metamorphism, causing flat or platy minerals (like mica) to realign perpendicular to the compression and form a layered fabric. The resulting rocks—slate, phyllite, schist, and gneiss—show this planar texture. It’s different from cleavage, which is a rock’s tendency to break along smooth planes, not a true reorientation of minerals. Luster and fracture describe surface shine and how a rock breaks, not the internal planar arrangement that defines foliation.