Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
46 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
What is a Mineral?
|
"a naturally occurring solid with a highly ordered atomic arrangement and definite (but not necessarily fixed) homogeneous chemical composition."
|
|
|
|
five main attributes of mineral:
|
1. naturally occurring
2. Solid 3. ordered atoms 4. definable chemical composition 5. homogeneous |
|
|
|
Minerals are commonly classified by_____ and not by ______ because _______
|
anionic complex, major cations, because compounds with the same anion share properties, where cationic families do not.
|
|
|
|
Minerals are named by:
|
1. physical property
2. major chemical aspect 3. color/appearance 4. etc |
|
|
|
What is the difference between diagnostic and Characteristic?
|
Diagnostic attributes occur in every specimen; characteristic in most.
|
|
|
|
What can the mineralogy of a rock tell us:
|
What the rock is,
How it formed, How it is useful |
|
|
|
How can mineralogy tell us how a rock was formed?
|
minerals have STABILITY LIMITS, which tell us at what temperature, pressure, and other physical conditions were present when the rock formed.
|
|
|
|
What is a crystal?
|
A chemically homogeneous solid with a 3 dimensional long range order.
|
|
|
|
What is Steno's Law of constant angles?
|
angles between corresponding faces on crystals are the same for all specimens of that mineral.
(interfacial angles) |
|
|
|
Define Unit Cell
|
a regularly repeating arrangement of atoms (similar to a monomer from O-chem) that affects the crystal structure. these are the unit of the crystal lattice.
|
|
|
|
What is the law of Bravais?
(draw picture) |
Faces of crystals are most likely to develope on strait lines through nodes in the lattice, and lines intersecting more nodes are more likely than those with less.
|
|
|
|
what types of bonding occur (molecular and atomic) in crystals. order from strongest to weakest.
|
1. covalent
2. ionic 3. metallic 4. hydrogen IMF 5. Vander Waals Forces |
|
|
|
what type of bonding occurs in silicate tetrahedra?
|
the bonds can be described with a covalent model, but is considered up to 50% ionic. it is the strongest X-O bond.
|
|
|
|
what is the basic unit of silica?
what is the most likely structure of two silica tetrahedra polymerized together? (draw) |
[SiO4]^4-
an hourglass shape, because the Si molecules are the farthest apart (minimizing the repulsion) |
|
|
|
What are the basic mineral groups of the silicate minerals?
|
Nesosilicates
Sorosilicates Cyclosilicates Inosilicates Phyllosilicates Tectosilicates |
|
|
|
Draw a nesosilicate unit.
what is an example mineral? |
[SiO4]^4-
garnet, olivine |
|
|
|
Draw a sorosilicate unit.
what is an example mineral? |
[Si2O7]^6-
epidote minerals |
|
|
|
Draw a cyclosilicate unit.
what is an example mineral? |
[Si6O18]^12-
Beryl/Emerald |
|
|
|
Draw a inosilicate unit.
what are the two types? what is an example mineral? common name? |
[SiO3]^2- [SiO2.5]^12- (part of unit cell)
single chain, double chain Augite chain silicates |
|
|
|
Draw a Phyllosilicate unit
What is an example mineral? common name? |
[Si2O5]^2- or [Si8O20]^8-
mica sheet silicates |
|
|
|
Draw a tectosilicate unit.
what is an example mineral? |
[SiO2]
quartz |
|
|
|
What are the top ten silicate minerals? what types are they?
|
olivine, garnet (Neso)
clino/orthopyroxene (Ino 1c) Hornblende (Ino 2c) Muscovite, Biotite (phyllo) Ortho/plagioclase, Quartz (tecto) |
|
|
|
What are the 8 most common elements in the earth's crust?
|
Si, Al, Fe, Ca, Mg, Na, K
|
|
|
|
what is the average thickness of the continental crust? the oceanic crust?
|
35km conitinental
7-10km oceanic |
|
|
|
what is the mineral composition of the upper mantle?
|
olivine, lesser pyroxene, trace aluminous minerals
|
|
|
|
rather than ordering the atomic components by name, how are mineral formulas written?
|
they are written to convey the structure of the molecule (in terms of the tetrahedral structure for most silicate minerals)
|
|
|
|
what is the chemical difference in the formulas for muscovite and biotite?
|
K(Mg,Fe)3(AlSi3O10)(OH)2 -biotite
KAl2(AlSi3O10)(OH)2 - muscovite they have different numbers of cations because of the charge difference. however, they still form sheet silicates. |
|
|
|
what is the cation composition of magnetite?
|
Fe 2+
2Fe 3+ makes Fe3O4, gives rise to it's magnetism. |
|
|
|
What are the names and formulas of the end members of Olivine?
|
Forsterite (Mg2SiO4)
Fayalite (Fe2SiO4) |
|
|
|
What are the names and formulas of the end members of Pyroxene?
What is unique about it's ternary diagram? |
Clinopyroxene:
Diopside (CaMg) - Hedenbergite (CaFe) Orthopyroxene: Enstatite (Mg2) - Ferrosilite (Fe2) |
|
|
|
What are the names and formulas for the end members of Garnet? (4)
|
Pyrope - Mg3(Al2Si3O12)
Almandine - Fe Spessartine - Mn Grossular - Ca |
|
|
|
What are the names and formulas for the end members of Amphiblole? (2)
|
Tremolite - Ca2(Mg)5Si8O22(OH)2
Actinolite (Fe) replaces (Mg) above |
|
|
|
What are the Controls on Solid Solution?
|
1. relative size of ions
2. ion charges 3. temperature and pressure 4. availability of ions |
|
|
|
What are the three types of solid solution?
|
1. substitutional (coupled and single)
2. Interstitial (occupied void) 3. Omission (high charged cation takes 2 spots - 1 empty) |
|
|
|
What is the formula for spinel?
|
Mg2Al2O4
|
|
|
|
What are the end members for Feldspar? draw the ternary diagram. Under what conditions do minerals in the swath occur?
|
Anorthite CaAl2Si2O8
Albite NaAlSi3O8 Orthoclase KAlSi3O8 double substitution occurs going up from albite to anorthite |
|
|
|
what are the four types of crystal symmetery? which is really a combination? notation?
|
mirror plane (m)
center (i) rotation axis (1,2,etc) roto-inversion (1, 2 with a bar) <- |
|
|
|
what is the difference between 2bar and m?
|
nothing. they are equivalent.
|
|
|
|
when should one check for a roto inversion?
|
when there is an axis of symmetry that does not have a perpendicular mirror plane. does not have to be the same number tho.
|
|
|
|
What are the seven crystal systems?
|
Triclinic - a x b x c, angles x equal
Monoclinic - a x b x c 2 angles =90 Orthorhombic - a x b x c all angles equal ninety |
Tetragonal - a = b x c all angles = 90
Hexagonal - angles a1 = a2 =a3 = 120 c = 90, a1 = a2 = a3 Isometric - all sides and angles equal trigonal - weird |
|
|
What is a point group?
|
external symmetry of an ideal crystal. these make up the crystal systems
|
|
|
|
draw the crystallographic axes.
|
x left y right z up, xint = a, etc. alpha is across from a, etc.
|
|
|
|
What is crystal habit?
|
Crystal habit describes a consistent developement of crystals in a rock. specifically, their shape.
|
|
|
|
What is cleavage?
|
Cleavage is the tendency of crystals to break along a predictable planes where the bonding is weaker.
|
|
|
|
What is an end member?
|
mineral composition that defines one limit of that compositional range
|
|
|
|
What are the two solid solution series for feldspar?
|
Alkali series - single substitution of K and Na
Plagioclase series - coupled substitution of Na and Si for Ca and Al |
|
