Types of Rocks
What are the three main types of rocks?
The three main types of rocks are igneous, sedimentary, and metamorphic.
What natural resource can be stored in rocks?
Water, oil, and natural gas can be stored in rocks.
What does porous mean?
Porous means having tiny holes through which fluids can pass.
What are rocks used for in construction?
Rocks are used for building materials, like granite for countertops and limestone for building facades.
What is the softest rock?
Talc is the softest rock, which is why it’s used to make talcum powder.
What is sedimentary rock?
Sedimentary rock is formed from particles of sand, shells, pebbles, and other fragments of material.
How is oil stored in rocks?
Oil is stored in the tiny spaces between the grains in sedimentary rocks.
What is permeability?
Permeability is a rock's ability to let fluids pass through its pores or cracks.
What can rocks tell us about Earth’s past?
Rocks can tell us about Earth’s past environments and the creatures that lived long ago through fossils.
How old are the oldest rocks on Earth?
The oldest rocks on Earth are about 4 billion years old.
What is igneous rock?
Igneous rock forms from cooled molten rock, either lava above the ground or magma below the ground.
What kinds of rocks are reservoirs for groundwater?
Porous rocks like sandstone are good reservoirs for groundwater.
What makes a rock hard or soft?
The mineral composition and how tightly the minerals are packed together determine a rock’s hardness.
Why are rocks important for soil?
Rocks break down over time to form soil, which provides nutrients and support for plants.
What rock floats on water?
Pumice is a rock that floats on water because it is full of air pockets.
What is metamorphic rock?
Metamorphic rock has been transformed by heat and pressure from another type of rock.
How does natural gas get trapped in rocks?
Natural gas can be trapped in the tiny spaces of porous rocks or beneath non-porous rocks that act as caps.
What is a rock's texture?
A rock’s texture refers to the size, shape, and arrangement of the grains or crystals in the rock.
What are precious stones made from?
Precious stones, like diamonds and rubies, are made from crystallized minerals under high pressure and heat.
What rock is magnetic?
Magnetite is a rock that is naturally magnetic, attracting iron.
How are sedimentary rocks formed?
Sedimentary rocks are formed by the accumulation and cementation of material on the Earth's surface, in bodies of water, or within bodies of sediment.
What role do rocks play in storing carbon?
Some rocks, like limestone, can store carbon absorbed from the atmosphere, helping reduce greenhouse gases.
What is crystalline texture in rocks?
Crystalline texture in rocks occurs when the rock is made up of minerals that have formed crystals that are interlocked.
How do humans use rocks to filter water?
Humans use porous rocks like sandstone in water filtration systems to help clean and purify the water.
Can rocks grow?
Rocks are nonliving so they don’t grow but they can increase in size. Rocks like stalactites and stalagmites grow in caves from mineral-rich water dripping and leaving deposits.