What are rocks?

●Solid material that consists of one or more minerals or other substances

●Classified based on how they were formed, their color, texture, and mineral
composition

●Three main types of rocks: Igneous, Sedimentary, and Metamorphic

●What do we use rocks for?

○Building materials, chalk, cement, artwork, roofing, railroads, etc.

What is the rock cycle?

●Rock Cycle: the continual process by which rocks can be changed into different
types of rock

●It can take millions of years for rocks to change form

Sedimentary Rocks

●Sedimentary Rocks: a type of rock formed through the accumulation,
compaction, and cementation of sediment

○Sediment: small pieces of rocks or other living things; formed from weathering and erosion

■Weathering: process by which exposed rock is broken down by rain, ice, wind, or other
elements of weather

■Erosion: the movement of weathered material by wind, water, or ice

○Accumulation: the gradual gathering of sediments

○Compaction: process by which overlying pressure from rocks and soil reduces the size or volume
of sediments (pressing the sediments together)

○Cementation: process of binding and hardening sediments into hard rock (like glue)

○Examples: Limestone and Sandstone

Igneous Rock
●Igneous Rock: a type of rock formed when crystalized (hardened) through
melting and cooling

○Crystalized: to change into a solid form that is made up of crystals

○Magma: molten rock underground

○Lava: molten rock on Earth’s surface

●Examples: Granite, Basalt, and Obsidian

Metamorphic Rock

●Metamorphic Rock: a type of rock formed when igneous or sedimentary rocks
are put under intense heat and pressure in the Earth’s crust

●Examples: Marble, Gneiss, and Slate

​https://www.youtube.com/watch?v=Vp_S3BDiR-I

​Click on this link to watch the video about the rock cycle.

Sources

The Science Duo

TEKS Resource System

https://chem.libretexts.org/Courses/Honolulu_Community_College/CHEM_100%3
A_Chemistry_and_Society/14%3A_Earth/14.01%3A_Spaceship_Earth-_Structure
_and_Composition