Weathering – This is the exposure of rocks and minerals to rain, wind, and chemicals in the soil.
Weathering can sometimes change the surface color of a mineral while the true color
remains hidden inside.
Hardness -
The resistance of the surface of a mineral to scratching by another substance.
Mohs’ scale - A ranking of a mineral’s hardness between the ranges of 1 to 10. One is the softest,
and ten is the hardest. This ranking is made based on the relative hardness of a
mineral.
Relative Hardness
The hardness of a mineral compared with the hardness of other common minerals.
For example, a mineral with a rank of 6 is harder than minerals with ranks of 1-5
and softer than a mineral with a rank of 7.
Rock -
It is made of more than one material. It may contain several kinds of
minerals as well as other organic materials. This is found in the earth’s crust.
Igneous Rock- One of the three main rock types—made when melted rock material cools and
hardens. May be quite porous, glassy, and may have random formations of minerals.
Sedimentary Rock – One of the three main rock types—made from small bits of matter joined
together. This matter may include bits of weathered rock, shell, sand, and/or remains
of living things.
Fossils -
The remains or imprints of living things, organic materials, of the past.
Metamorphic Rock - One of the three main rock types—formed under heat and pressure when one
Rock changes into another. The mineral grains MAY line up and separate into layers.
Magma -
Hot, melted rock deep below Earth’s surface
Lava -
Magma that reaches the Earth’s surface
Deposition- The dropping off of bits of eroded rock.
Delta -
The mouth of a large river—the area where deposition takes place
Erosion -
All the processes by which soil and rock are loosened and carried away. Examples
of this include wind, water, and ice.
Physical Weathering -
The breaking down of materials of the Earth’s crust into smaller pieces.
This can happen through water, ice, wind, and temperature changes.
Chemical Weathering -
The air reacting with chemicals such as carbon dioxide and sulfur dioxide
reacting with water (rain) to form acid rain. This eats away at rocks such
as limestone.
Rock Cycle -