Transcript Chapter2rocksandmine..

Chapter 2 Minerals
Minerals
1. A mineral is an inorganic (not formed
from living things), solid material found in
nature that has a definite crystal
structure. There are 4000 different
minerals, most of which are made up
from a combination of only 8 elements.
2. Rocks are usually made up of two or
more minerals.
Dietary Minerals
• any of a group of inorganic elements that are
essential to humans and animals for normal
body function.
• Dietary minerals are derived from the earth's
crust. Plants extract the minerals from the soil,
and humans and animals, in their turn,
consume the plants.
• Calcium, Phosphorus, Magnesium, Sodium,
Chlorine, Potassium, Sulfur, Iron, Cobalt,
Chromium, Copper, Fluorine.
•
http://nutrition.about.com/library/bl_minerals_quiz.htm
Mineral Formation
Minerals form in many different ways.
- melted rock inside the earth (magma).
- melted rock that reaches the earths
surface (lava).
-evaporation of water leaving minerals
behind. (ocean water, salt in cup after
ocean water evaporates)
- precipitation of minerals suspended in
water. (manganese nodules in ocean)
Properties of Minerals
Physical properties are identifiable
items such as color, size, and texture;
things that can be observed or measured
without changing or attempting to change
the material.
1. Crystals are solid minerals that have an
orderly pattern of atoms. Crystal size and
shape are very important identifying
physical properties.
2. Cleavage and fracture is another clue
to a minerals identity. In the way the
mineral breaks defines what type of
mineral it might be.
Cleavage - split into pieces with smooth,
regular planes that reflect light.
Fracture – mineral that breaks into
pieces with jagged or rough edges
3. Color – offers a valuable way to identify
mineral. Color can also be confusing, for
example fools gold (pyrite) has the same
color as real gold.
4. Streak and luster – Streak is when a
sample is scraped across an unglazed,
white tile, called a streak plate. Based on
the color of the streak left on the plate
you can better identify the mineral.
Luster is how shiny, dull, or pearly a
mineral is, based on how it reflects light.
Hardness – minerals can be
separated by how hard they are.
This is done by doing a scratch
test using the Mohs scale of
hardness.
Density– The amount of matter in
a given space. Mass per unit of
space.(heft) is how heavy a rock
is compared to an equal amount
of water.
Common MO Minerals
Galena (lead)
Fire Clay
Lime
Cement
Copper
Barite
Zinc
Iron Oxide
Gemstones – are minerals that are rare and
can be cut and polished, giving them a
beautiful appearance.
Ores – minerals that can be sold for a
profit.
Rock cycle – the continuous changing
of rocks from one kind to another over
a long period of time
Rocks
1. Igneous Rock – form when melted rock
from inside Earth cools.
a) Extrusive igneous – melted rock
cools on the Earth’s surface. Small
crystal sizes
Ex. Basalt
b) Intrusive Igneous - Melted rock that
cools below Earth’s surface. Larger
crystal sizes
Ex. Granite
Classifying igneous rocks
1. Crystal size
- fine grained crystals
- coarse grained crystals
- porphyritic (large and small
crystals)
2. Mineral composition
- light colored
- dark colored
3. Metamorphic Rocks – New
rocks that form when existing
rocks are heated or squeezed.
(Metamorphic means to change
form)
Granite to gneiss
two types Foliated gneiss
Nonfoliated marble
2. Sedimentary Rocks – Pieces of
broken rock, shells, mineral grains,
and other materials that collects in
layers to form rock.
Detrital sedimentary rock – fragments of
weathered rocks compacted and cemented
together. Conglomerate, sandstone,
siltstone, and shale are forms of detrital rock.
From coarse pebbles to fine clays. Classified
based on sediment size that forms the rock.
Chemical sedimentary rocks – formed when
dissolved mineral come out of solution.
Calcium carbonate is carried in solution in
ocean water When calcium carbonate comes
out of solution as calcite and many crystals
grow together forms limestone.
Organic sedimentary rocks – rocks made of the
remains of once-living things. Chalk is an
organic rock made of microscopic shells.
Fossils are the major makeup organic rock.