Download Geology is all around you

Geology is all around you!
Whether you know a lot about geology or just a little, you probably know that the
Earth’s crust and the material below it are made up of rocks and minerals. There
are hundreds of varieties of rocks and minerals and each one has its own unique
history from the time it was formed to the time someone finds a specimen and
adds it to their collection.
Minerals
Minerals are solid objects that are formed in nature and have
never been alive. There are many different minerals, and not two
kinds are exactly alike. Rocks are a group of minerals that are
found together. The type of rock is determined by the type of
minerals that are formed together along with the place where
they are created, such as deep in the Earth’s crust or near the surface. For
example, quartz, feldspar and mica are individual minerals, but when they are found
together in a rock that formed underground, it is often called granite.
Some minerals are very common and some are rare. Minerals come in many shapes,
sizes, and lusters. Gold, for example, is shiny. Other minerals are dull and dark.
Some minerals can be shaped like cubes or pyramids. Minerals are used for many
purposes. Some minerals, like gypsum, are used to make cement. Mica is used in
paints and quartz is used in watches and other electronics. Other minerals are used
for jewelry and are considered precious (diamond, emeralds, and ruby) or semiprecious (citrine, garnet, and peridot) gemstones based on how easy they are to
find.
Rocks
What are hills, beaches, and the ocean floor all made of? Rocks! Rocks are found
everywhere on Earth. You’ve probably seen many different kinds of rocks. All of
them have one thing in common—minerals. A rock is a naturally formed solid
made of grains of one or more minerals.
There are three types of rocks in the world which are:
Sedimentary
Sedimentary rocks are formed when sand, small pieces or rock,
or mud are pressed together to form layers of sediment.
These layers of sediment are pressed together over a long
period of time and form a sedimentary rock.
Igneous
Igneous rock forms from hot liquid magma. The magma erupts
from a volcano, cools and hardens into igneous rocks. When the
hot magma is trapped beneath the earth’s surface, it cools and
hardens to form igneous rocks inside the earth.
Metamorphic
A metamorphic rock is formed when a sedimentary or igneous rock changes form
because the temperature or pressure changes. This change typically occurs over
time when the sedimentary or igneous rocks are buried beneath the earth’s
surface.
The type of rocks and minerals present in an area and the type of fossils found can
help tell us about the Earth’s history. Through the rock and fossil record a
scientist can tell the age of the rock and the time period when the plant or animal
that made the fossil lived. The oldest rocks are known to be approximately 600
million years old!