Minerals Flashcards
What are the requirements for classifying something as a mineral?
- Is naturally occuring
- Is solid
- Is inorganic (non-biogenic)
-Has specific chemical composition
-Has an orderly atomic arrangement (aka regular crystalline structure characterized by groups of atoms arranged in periodic repetition).
What are the four types of electron bonds?
Covalent (electron-sharing), Ionic (electrostatic attraction), Metallic and Van Der Waals
Generally, covalent bonds happen between what two types of elements? How about ionic bonds?
Covalent bonds are generally between two non-metals and ionic is a metal and a non-metal.
What are the ways minerals can form?
Precipitation
Crystallization
Metamorphism
Weathering
Organic formation
What is the weakest type of electron bond? The strongest?
Weakest is Van der Walls, strongest is covalent.
In terms of forming minerals, what is precipitation?
It is from an aqueous solution with the change in temperature
In terms of forming minerals, what is crystallization?
From lava/magma with a change in temperature.
In terms of forming minerals, what is metamorphism?
formation of new minerals directly from the elements within existing minerals under conditions of elevated temperature and pressure. Usually happens underground.
In terms of forming minerals, what is weathering?
Mechanical weathering or chemical weathering. interaction with other elements. during which minerals unstable at Earth’s surface may be altered to other minerals
In terms of forming minerals, what is organic formation?
formation of minerals within shells (primarily calcite) and teeth and bones (primarily apatite) by organisms.
NOTE: these organically formed minerals are still called minerals because they can also form inorganically
What are the what are the 8 elements that mostly make up the earths crust?
Oxygen (46%), Silicon (28%), Aluminum (8%), iron (6%), Magnesium (4%), Calcium (2.4%), Potassium (2.3%), Sodium (2.1%).
The rest is less than 1% of “other”.
What are the 8 types of rock forming minerals?
- Silicates - 90% of crust, containing Si & O. Tectosilicates are 70%
- Native elements - precious metals (Au, Ag…)
- Carbonates - CO3, calcite, dolomite
- Oxides - contains O. hematite, magnetite
- Sulfides - contain S.
pyrite - Sulfates - SO4. gypsum
- Phosphates - PO4.
apatite - Halides - contains halide anion F-, Cl-, Br-, I-. halite
What are the properties of minerals determined by?
Specific chemical composition (color, density, magnetism) & orderly atomic structure (form, breakage, hardness)
In terms of mineral properties, protons/neutrons are responsible for ____________.
density
In terms of appearance, electrons are responsible for ____________ & __________.
hardness & color
Color can be due to e- transfer
A _________________ is a mineral with the same chemical composition but a different internal structure.
polymorph.
An example would be graphite and diamond
What are two ways that a minerals “streak” can be used?
Streak is the true color of a mineral, disregarding an impurities.
Can be used to distinguish between minerals that have similar colors
Can be used to compare the same
mineral that may occur in a variety of colors
A mineral with a (strong/weak) color & streak contains
abundant transition
elements.
strong
What is the difference between cleavage and fracture?
Cleavage signifies a lack of uniformity in the strength in the bonds, so the mineral will break on specific planes that are even and uniform.
Fracture means that all the bonds are of equal strength, so the mineral will break irregularly
What are the 5 types of cleavage?
Basal (single plane), prismatic (two planes), cubic, rhombohedral (like cubic but not 90 degree angles), octahedral (4 directions)
So long as a mineral has at least (one/three) smooth flat surface along which is broke it is considered to have cleavage.
one
T/F: When determining the number of
cleavage directions , count the number of
surfaces (i.e., planes) that are
parallel.
F - that are NOT parallel
What is hardness in terms of mineral properties?
is the resistance to abrasion or being scratched
- Hardness is related to the strength of a mineral’s weakest bond
- It is classified on the 10-pt Mohs Hardness Scale.
- It can sometimes vary in different directions for the same mineral (i.e., kyanite).
- Minerals in which covalent bonds dominate will be harder than those with those in which ionic
bonds dominate.
What are some aspects of the silicate mineral group?
- Basic component of all silicate minerals is the silicon-oxygen (Si-O) tetrahedron = 1 silicon cation (Si-4) surrounded by 4 oxygen anions (O-2) in a 4-sided pyramid.
- This tetrahedron has a net charge of -4 and is written as (SiO4)-4
- This charge is balanced by the addition of metals which are positively charged
- Different combinations of metals and tetrahedrons within the crystal
structure create the major subclasses of silicate minerals. - Each subclass has a general set of physical properties which aid in the recognition of silicate minerals within a given subclass
What is crystal form in terms of mineral properties?
Crystal form is how the minerals form (how they look) if space is not an issue. Also called crystal habit.
What does “luster” describe and what are its two classes?
describes the character of light that is reflected from a fresh mineral surface.
Can be metallic or nonmetallic
After initially determining if the luster resembles that of a metal (or does not), the type of luster
exhibited can be more specifically described……
- For metallic (choose either metallic vs submetallic) and for non-metallic (choose from adamantine, resinous, vitreous,
pearly, silky, greasy, dull, etc.).
What common mineral reacts with HCl at room temperature?
Calcite
Diamonds are part of the native element group of minerals. T/F
True - native element group are minerals that are made up of a single element. Copper, gold, sulfur, silver are other examples
The relative scratchability of a mineral is called?
hardness
The mineral group sulfates are grouped together based a similar chemical component of:
A) SO4
B) S
C) SiO
D) CO3
E) none of the above
SO4
Theories are not considered facts by the scientific community. T/F
T
A substance with a random arrangement of atoms are considered:
A) minerals
B) amorphous substances
C) Calcite
D) voluminous substances
E) none of the above
B) amorphous substances
Explain what polymorphs are including a specific example. Why are they important?
Polymorphs are minerals that have the same chemical composition but different physical properties. They are important because it can help inform you about the environmental that produced the mineral.
What are some members of the Oxide group? What are there chemical formulas?
Hematite (Fe2O3)
Magnetite (Fe3O4)
Corundum (Al2O3)
Ice (H2O)
Chromite (FeCr2O4)
Ilmenite (FeTiO3)
What are some members of the Sulfide group? What are there chemical formulas?
Galena (PbS)
Sphalerite (ZnS)
Pyrite (FeS2)
Chalcopyrite (CuFeS2)
Bornite (Cu5FeS2)
Cinnabar (HgS)
What are some members of the Sulfates group? What are there chemical formulas?
Gypsum (CaSO4 * 2H2O)
Anhydrite (CaSO4)
Barite (BaSO4)
What are some members of the Halides group? What are there chemical formulas?
Halite (NaCl)
Fluorite (CaF2)
Sylvite (KCl)
What are some members of the Carbonates group? What are there chemical formulas?
Calcite (CaCO3)
Dolomite (CaMg(CO3)2)
Malachite
(Cu2(OH)2CO3)
Azurite (Cu3(OH)2(CO3)2)
What are some members of the Hydroxides group? What are there chemical formulas?
Limonite (FeO(OH) *nH2O)
Bauxite (Al(OH)3 * nH2O)
What are some members of the Phosphates group? What are there chemical formulas?
Apatite (Ca5(F,Cl,OH)(PO4)3)
Turquoise (CuAl6(PO4)4(OH)8)
Olivine - what is the idealized formula & the silicate structure?
(Mg,Fe)2SiO4 - single tetrahedron
Pyroxene group (augite) - what is the idealized formula & the silicate structure?
(Mg,Fe)SiO3 - single chains
Amphibole group (hornblende) - what is the idealized formula & the silicate structure?
Ca2(Fe,Mg)5Si8O10(OH)2 - double chains
Mica - Biotite - what is the idealized formula & the silicate structure?
K(Mg,Fe)3AlSi3O10(OH)2 - sheet silicate
Mica - Muscovite - what is the idealized formula & the silicate structure?
KAl2(AlSi3O10)(OH)2 - sheet silicate
Feldspar - Orthoclase - what is the idealized formula & the silicate structure?
KAlSi3O8 - 3D networks, complex structure
Feldspar - Plagioclase - what is the idealized formula & the silicate structure?
(Ca,Na)AlSi3O8 - 3D networks, complex structure
Quartz - what is the idealized formula & the silicate structure?
SiO2 - 3D networks, complex structure
When Si-O tetrahedron bond together by sharing oxygen atoms to create complex chemical structures this is called ________________.
polymerization
