If you're hunting for Rocks, Minerals, and Fossils,
you've hit the Mother Lode! At Mother
Lode Rock Shop, you get to pick. Choose the
exact specimens you want from our wide-ranging collection of Rocks, Minerals, and Fossils.
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more Rocks, Minerals, and Fossils.
are the building blocks
of rocks. A mineral is a
naturally occuring solid compound usually
two or more
chemical elements. A few minerals, such as
silver, and sulfur, occur as single "native"
Minerals are defined both by their chemical formula
and by their internal
crystal structure. For example, iron
sulfide has the formula FeS2, where F is iron
and S is sulfur. Iron sulfide, like many other minerals, can
crystallize in different ways. When it crystallizes in
a cubic system, it forms the mineral pyrite. When it
crystallizes in an orthorhombic system, it forms the mineral marcasite.
Watch this 10-minute video to learn more about
The Mohs Hardness Scale
is a qualitative scale used to rank the hardness of a mineral
by comparing its scratch
resistance to other minerals. It was developed
in 1812 by the German geologist Friedrich
Very easily scratched by a fingernail
Can be scratched by a fingernail
Just scratched with a copper coin
Very easily scratched with a knife
Scratched with a knife with difficulty
Cannot be scratched with a knife but
scratches glass with difficulty
Scratches glass easily
Scratches glass very easily
and the Rock Cycle
A rock is a
naturally occurring aggregate
of one or more minerals.
Rocks are classified into 3
basic categories: igneous,
sedimentary, and metamorphic.
rocks form from molten
rock (lava or
magma). Examples include granite and basalt.
rocks form by the deposition
organic or inorganic material, either from sediments
formed by the
weathering and erosion of other rocks, or by chemical precipitation
from a solution. Deposits are laid down by water, wind, or
ice, usually in layers or strata. Examples include sandstone
rocks form when the composition,
texture, or structure of existing rock is changed by extreme
temperature, extreme pressure, or both. Examples
The process by which rocks are formed, eroded, and reconstituted into
new rocks is called The
Image courtesy of U.S. Geological Survey
The rigid outer shell of
the Earth, called the lithosphere,
is broken into giant slabs of rock called tectonic plates.
The plates move
gradually over time, driven by convection currents
inside the Earth's mantle.
The Earth's history is divided into time intervals called Eons, Eras,
and Periods. The boundaries between each interval reflect
important events, such as global extinctions of plant and animal
species, or the first appearance of certain species on the fossil