Which of the following types of rocks is part of the "I SMASH Rocks" mnemonic?

• A. Metamorphic
• B. Obsidian
• C. Granite
• D. Coal

Answer: (A)

The correct type of rock included in the "I SMASH Rocks" mnemonic is metamorphic. This mnemonic is used to help remember the three main types of rocks: igneous, sedimentary, and metamorphic. In this context, the “M” in "I SMASH" specifically stands for metamorphic rocks.

Metamorphic rocks are formed from existing rocks that undergo a transformation due to high temperature, high pressure, or chemically active fluids. Common examples of metamorphic rocks include schist and gneiss. This transformation alters the mineral composition and texture of the original rock without completely melting it, distinguishing it from igneous or sedimentary processes.

While obsidian is an example of an igneous rock, granite is also an igneous rock, and coal is classified as a sedimentary rock. Therefore, these options do not fit within the context of the mnemonic that specifically highlights metamorphic rocks. Understanding where metamorphic rocks fit into the larger classification system of rocks helps reinforce the concepts behind the rock cycle and geological processes.