metamorphic rock

1. Rock that was once one form of rock but has changed to another under the influence of heat, pressure, or some other agent without passing through a liquid phase.

Examples are marble, which can be formed from limestone, and slate, which is formed from shale.

Example Sentences

It’s the sturdy metamorphic rock that underlies the Los Angeles Basin, “the bedrock of this whole area,” Coffey says.

Read more on Los Angeles Times

It’s a metamorphic rock, which means it becomes something new under extreme heat and pressure without melting.

Read more on National Geographic

The person with knowledge of the matter said that the group’s name derived from the metamorphic rock, signaling the group’s intent to be enduring and maintain a clarity of purpose.

Read more on New York Times

Equipment designed for the softer, cooler sedimentary rock often found in oil fields falters in the extremes of hot, hard metamorphic rocks such as granite.

Read more on Science Magazine

Marble, the metamorphic rock, embodied for me a dark paradox: It is change that produces changelessness.

Read more on New York Times