Any type of rock or soil that was formed from molten or melted rock is a(n) ________.

Any type of rock or soil that was formed from molten or melted rock is a(n) ________.

• A. Sedimentary
• B. Metamorphic
• C. Igneous
• D. Mineral

Answer: (C)

When rock or soil is formed from molten material that has cooled and crystallized, it is igneous. The molten material, called magma when underground or lava when it erupts onto the surface, cools and minerals crystallize into solid rock. The speed of cooling shapes the texture: slow cooling underground yields coarse grains (like granite), while rapid cooling at the surface creates fine grains (like basalt or rhyolite) or even volcanic glass (like obsidian). This origin is distinct from sedimentary rocks, which form from cemented or compacted sediments, and from metamorphic rocks, which form from existing rocks altered by heat and pressure without melting. If melting occurs and the material later solidifies, the end product is igneous.

When rock or soil is formed from molten material that has cooled and crystallized, it is igneous. The molten material, called magma when underground or lava when it erupts onto the surface, cools and minerals crystallize into solid rock. The speed of cooling shapes the texture: slow cooling underground yields coarse grains (like granite), while rapid cooling at the surface creates fine grains (like basalt or rhyolite) or even volcanic glass (like obsidian). This origin is distinct from sedimentary rocks, which form from cemented or compacted sediments, and from metamorphic rocks, which form from existing rocks altered by heat and pressure without melting. If melting occurs and the material later solidifies, the end product is igneous.