Amazing Facts About
Rocks!
By Chelsea McPherson
Adapted by Chelsea Downie, Katie DiRe, Becky Ruddy, Kelly Schultz, and
Holly Im-Hamper
What is a person called who studies
rocks?
A geologist is a scientist who
studies rocks and earth
materials.
They use a hammer to separate rocks
and look at the different layers.
They use a magnifying glass or a
microscope to better observe the
properties.
How are rocks formed?
One way rocks are formed is from lava
coming out of an erupting volcano.
When the lava hardens, it separates and
forms 3 different rocks. They are
basalt, tuff, and scoria.
Two properties of basalt are gray and
smooth. Basalt comes from the lava.
Properties of tuff are white and dusty
and it comes from the ashes of a volcano.
Scoria comes from the bubbly
lava and its properties are red
and rough. Can you see all the
holes?
Another way rocks are formed is by
erosion. Erosion is when the wind, the
rain, and the sun break away the earth’s
surface and make rocks over time.
Erosion turns a boulder into a cobble.
Erosion turns a cobble into a pebble.
Erosion turns a pebble into gravel.
Erosion turns gravel into sand.
Erosion turns sand into silt.
Erosion turns a silt into clay.
Can you name earth materials from
biggest to smallest?
A boulder is bigger than 2 hands.
A cobble fits in your hand.
A pebble is about the size of popcorn.
The next 4 are gravel, sand, silt
and clay.