Obsidian is a glassy black igneous rock. A sample of obsidian is shown. Which type of rock forms in a similar manner as obsidian but at a slower rate?

Question

1.schist, which forms under extreme heat and pressure

2.conglomerate, which forms when different-sized sediments cement together

3.gypsum, which forms when water evaporates and leaves behind minerals

4.granite, which forms as magma cools deep underground

Answer 1

4. granite, which forms as magma cools deep underground