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*Minerals
- characteristics: -Naturally occurring
- - solid substance
- - orderly crystalline structure
- - well-defined chemical composition
- -generally inorganic
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*Naturally occuring
formed by natural geologic processes. Not synthetic
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*Solid substance
minerals need to be solid within temperature ranges normally experienced at earths surfaces.
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*Orderly crystalline structure
means their atoms are arranged in a orderly repetitive manner.
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*Well-defined chemical composition
means that chemical composition of a mineral may vary, but has to be wihin a certain limit or well defined limit.
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*Generally inorganic
inorganic crystalline solids, such as table salt is found naturally on ground.
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Valence electrons
are electrons located on the outermost shell. Interact with other atoms to form chemical bonds
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Atomic number
number of protons in the nucleus of an atom, it determines its chemical nature
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Chemical compounds
variety of elements joined together to form something
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Octet rule
Atoms tend to gain, lose, or share electrons until they are surrounded by 8 valence electrons
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Chemical bond
is the transfer or sharing of electrons that allows atoms to attain a full valence shell of electrons.
three types: Ionic, covalent, hydro
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Ionic bond
is when valence electrons are transferred between the elements to form ions
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Covalent bond
is when electrons SHARE between the atoms
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IONs
Positive ions: Cations
Negative Ions: Anions
- Atoms that lose electrons are Cations
- Atoms that gain electrons are Anions
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Ionic compounds
oppositely charges ions are strongly attracted to one another.
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Mass number
is total number of protons and neutrons in a atom
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Isotopes
are atoms with same protons but different amount of neutrons
carbon 12, carbon 13, carbon 14
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Physical properties of minerals: Optical properties
Luster, the ability to trasnmit light, color, and streak are most frequnetly used for mineral ID
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#Luster
appearance or quality of light refelcted from the surface of a mineral
Metallic or nonmetallic
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#Ability to trasnmit light
Opaque: no light is permitted
Translucent: light but no image
Transparent: both light and image are permitted
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Color
it can be misleading in identifying minerals. There are numerous of rocks that have different colors.
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Streak
is when a rock or mineral is rubbed on a streak plate, leaving color powdered mineral behind.
helps distinguish between metallic luster or nonmetallic luster
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Tenacity
describes mienrals toughness, or its resistance to breaking or deforming.
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Hardness
measure of the resistance of a mineral to abrasion or scratching.
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Mohs scale
10 objects. diamond is the hardest.
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Cleavage
tendency of a mineral to break along planes of weak bonding
not all minerals have cleavage
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Fracture
when some minerals fracture they create uneven surfaces or smoothed curves.
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Specific gravity
it is unitless representing the ratio of a mineral weight to the weight of an equal volume of water
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