* Sedimentary rocks are formed from the accumulation and cementation of sediments like sand, silt, clay, and fragments of other rocks. These sediments are often small and loose.
* Metamorphic rocks form when existing rocks (igneous, sedimentary, or even other metamorphic rocks) are subjected to intense heat and pressure deep within the Earth's crust. This process causes the minerals within the rock to recrystallize and grow larger.
Here's a breakdown:
* Sedimentary rocks: The particles are usually smaller, ranging from microscopic (clay) to millimeters (sand).
* Metamorphic rocks: The particles can range from millimeters to centimeters or even larger, depending on the specific type of metamorphic rock and the degree of metamorphism.
Examples:
* Sedimentary rock (sandstone): Composed of sand grains, typically less than 2 millimeters in diameter.
* Metamorphic rock (marble): Formed from limestone, with large, interlocking calcite crystals.
Important Note: There are exceptions to this general rule. Some metamorphic rocks, like slate, can have very fine-grained textures, while some sedimentary rocks, like conglomerate, can have large particles.
