Download Minerals: Naturally occurring solid with a crystal structure and a

Minerals:
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Naturally occurring solid with a crystal structure and a unique set of properties
Crystal structure is made of molecules arranged in a regular repeating pattern
Ex: Topaz, Quartz, Diamond
Physical Properties:
o Hardness
o Luster
o Color
o Streak (the color left on a streak plate from rubbing)
o Density
o Crystal shape
o Cleavage and fracture
Rocks:
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Solid mixture of crystals of one or more minerals
Often classified into groups depending on the mineral it contains
Composition is its chemical make-up (combination of minerals of which it is made)
4 textures:
o Glassy= no crystals
o Fine-grained= small crystals or grains
o Porphyritic= both large and small grains
o Coarse-grained= large crystals or grains (larger than pebbles)
 The texture depends on the shape and position of the minerals
 3 Types:
o Igneous
 Formed when minerals in magma cool and harden
 Size of the crystals determines the texture; texture depends on the time it
takes to harden (cool)
 Volcanic glass will not have crystals
 Can be found beneath the Earth’s surface, islands, volcanoes, and
bordering magma chambers
 2 Types:
 Intrusive- formed from magma inside the earth
 Extrusive- formed from lava that cools on the Earth’s surface
o Sedimentary
 Formed when pieces of rock are carries and deposited by wind or water,
then cemented (fused) together by pressure
 May contain fossils
 Tend to be soft rocks
 Sometimes show layers
 Ways sediments can be produced:
 Animal burrowing
 Wind
 Water
 Glacier movement
 When water gets into cracks of rock and freezes/ expands to break
the rock
 3 types:
 Clastic= forms over time from pressure and cementing. Ex:
sandstone, shale, siltstone
 Chemical= form when mineral come out of a solutions and settle on
the ocean floor. Ex: limestone, coquina
 Organic= forms from the remains of once living things. Ex: coal
o Metamorphic
 Formed when rocks are chemically changed due to heat, pressure, or both;
the rock does not get hot enough to melt
 Tend to be hard rocks
 The new rock properties are different from the original rock
 2 types:
 Foliated= banded/ visible layers. Ex: slate, schist, gneiss
 Non-foliated= no bands/ no visible layers. Ex: marble, quartzite