Mineralogy midterm 1

Levinson Rule

The REEs behave similarly, sothey can substitute in mineralsfor each other.• REEs: lanthanides + Y (not Sc)

mineralloid

lacks homogenous solid or crystalline parts of mineral definition. ex: gels, glasses, radiation damaged crystals

Suppose a crystal shows no planar faces at all. What's a good word to describe it?

anhedral

Crystal form and crystal habit

Tendency to show crystal faces: euhedral, subhedral anhedral (if individual xls are visible)
General names for the shapes of individual crystals

AGGREGATE habit

General names for shapes of aggregates of xls. Individual crystals may or may not be visible

sectile tenacity

can be carved with a knife

Give three examples of important sulfide minerals.

Pyrite (FeS₂)
Chalcopyrite (CuFeS₂)
Galena (PbS)

What are two important sulfate minerals, and two importantphosphate minerals? What makes a sulfate a sulfate, and aphosphate a phosphate?

Gypsum (CaSO₄·2H₂O)
Barite (BaSO₄)

Apatite (Ca₅(PO₄)₃(F,Cl,OH))
Monazite ((Ce,La,Nd,Th)PO₄)

Sulfate minerals contain the sulfate ion. This ion consists of a central sulfur atom surrounded by four oxygen atoms in a tetrahedral arrangement,

Phosphate minerals contain the phosphate ion. This ion consists of a central phosphorus atom surrounded by four oxygen atoms, also arranged in a tetrahedral geometry.

Draw the structures of a sorosilicate, a single chain inosilicate, and anesosilicate. What's the essential 'brick' of a silicate structure?

What do you need to do in order to determine if a mineral is thermoluminescent?

grind to powder. heat to high temp, measure luminescence

Suppose a substance is crystalline, but you can't see the individual crystals even under a microscope. A good name for this is what?

massive or cryptocrystalline

Petrology

sedimentary, igneous, metamorphic rocks are composed almost entirely of minerals (also space [pores], organics, fluids)

How many mineral species are tehre?

6062

What is a mineral?

D definite chemical composition OR range of compositions
I inorganic
S solid and homogenous
C crystalline substance(highly ordered atomic arrangement)
O naturally occuring (exceptions include things liks calcite, apatite, magnetite)

Type locality (Latin locus typicus)

typical or representative location.• It is NOT necessarily the first location where the mineral was discovered.

what can minerals be named for (CNMNC)

places, features, individuals(not yourself)
must end in -ite
can be abolished or renamed
can be discredited if duplicated, a mixture, or noncrystalline

common anionic groups

carbonate CO3-2
phosphate PO3-3
sulfates SO4-2
silicates SiO4-4
hydroxides (OH)-1
arsenates AsO4-3
tungstates WO4-2

amorphous

not highly arranged assortment of atoms. ex: amber, coal. obsidian

denstiy units

g/cm^3

Crystal

a homogeneous solid that possesses long range, 3-D order

Morphology

The external shape and form of a crystal

Euhedral

Good crystal faces; grown in open cavity.

Subhedral

Crystals have some well formed faces and some poorly formed faces

Anhedral

grown in tight space, no crystal faces

Scale of crystallinity

Mesoscopic
microcrystalline
Submicroscopic

Group (= family)

a collection of species, sharing chemistry or structure. "olivine", "garnet", "feldspar", "silicates"

mineral species

A collection of specimens that exhibit similar internal structure and chemical compositions

If a set of crystals of some mineral are all less than 1micron in diameter, what name would you use to describe them?

nanometer

Name three mineral families or groups, and three mineral varieties.

silicates, carbonates, oxides
quartz, calcite, corundum

What are the charges on Cl and Mg? Are they cations, anions?

Cl is an anion with a −charge
Mg is a cation with a +2 charge.

What's the name of 10-9 meters?

nanometer

crystallization

when gases or liquids form crystal, halite in water, sulfur from volcano

Special crystal features

Parallel growth features
Hoppers
Curved crystal faces
Twins
Striated crystal faces
Phantom crystals

Fracture

How a mineral breaks.If no cleavage, then only fracture. Minerals with good cleavage may not show fracture very well

Hardness

Mohs scale, 1-10. Relative system.

brittle (tenacity

fractures and powders readily

flexible tenacity

can bend but does not return to original shape

elastic tenacity

bends and does return to original shape

What are the two commonly used mineral classification schemes,and who were they named after?

Dana Classification: Named after James Dwight Dana, an American geologist and mineralogist.

Strunz Classification: Named after Carl Heinrich Strunz, a German mineralogist.

What mineraloid in the Dana classification was formed at only onemoment in history, in 1945?

trinitite

In the Dana classification, the fairly common mineral siderite isclassified 14.1.1.3. What does each number represent?

14: This is the major group number, indicating the Carbonate minerals.
1: This number specifies the subgroup within the major group, which in this case is Simple Carbonates.
1: This is the series number, denoting Carbonates with the general formula AB(CO₃)₂, where A and B are typically metal cations.
3: This is the specific mineral species number, identifying Siderite within this series.

What's the difference between a hydroxide and an oxide mineral?

hydroxide minerals have hydroxide ions (OH)- in their structure, while oxide minerals have oxide ions (O2)-

Which of the following illustrates the conceptof 'appropriately dealing with uncertainty' and/orunderstanding the limitations of physical tests?

E

a) realizing that if your specimen contains a mixture of minerals, it's not possible to accurately gauge s.g.
b) noting that in microcrystalline aggregates of some mineral, it's not possible to determine either xl habit or the number of cleavages present
c) recognizing that if part of crystal is missing or the crystal is anhedral, it's not possible to uniquely determine the crystal habit
d) understanding that if the hardest tool you have is a pieceof quartz, and a mineral specimen is harder than yourquartz, the H of the specimen is poorly constrained to bemerely >7.
e) all of the above

Identifying, recognizing, & naming the crystal habit

A

a) Involves spotting the individual crystals, then describing the shape they collectively form
b) Involves determining if the collection of grains is solely one species, then identifying the direction the grains align
c) Is like giving a name to the shape defined by abouquet of flowers, whether or not you can see the individual flowers
d) Is predicated on first figuring out if the grains are euhedral, anhedral, or subhedral
e) None of the above

The smallest type of colloform aggregate habitis

C

a) Mammillary
b) Botryoidal
c) Globular
d) Reniform

Explain the basics of what happens in tenebrescence, which requires one to do what to the specimen first?

expose the specimen to ultraviolet (UV) light

How do short range and long range order differ? Which one do minerals have?

long range- minerals- atomic arrangement is consistent, repetitive patterns througout the entire crystal.

short range is less organized with less ordering kinda amorphous crystals

paleontology

mineralization of organic remains

Seismology

waves traveling through rocks, controlled by the physics of the minerals

Economic geology

economically valuable minerals

Hydrogeology & environmental geology

how water interacts with minerals

Structural geology

how a rock deforms depends on what minerals it is made of

It's not a mineral until..

it has been described and characterized in publication

what portion of minerals are silicates?

1/3

native elements

' (Fe,Ti, Cu, Au, Ag, Bi, In, As, Bi, Se, etc.) or mixtures of metals (but no anions)• Non-metals: (sulfur, diamond, graphite).

Crystallography

study of this long-range order: affects physicalproperties

variety

version of a species showing something not all crystals of that species have.

The external shape and form of a crystal is called its what?

crystal habit

A group of minerals with formulas ending in PO4-3 would be called what?

phosphates

Cleavage

tendency of mineral to repeatedly split parallel to atomic planes

possible cleavage numbers

1 basal
2 rhombohedral
3 cubic
4 octahedral
6 dodecahedral

Parting

Like a poor cleavage, sometimes present, sometimes not.

Tenacity

Resistance to breaking, crushing, bending, or tearing.

malleable tenacity

hammered into thin sheets

ductile tenactiy

can be drawn into a wire

opacity

opaque (no light)
translucent (light but no image)
transparent (can see image)

Streak

the color of a mineral's powder

Luster

The way a mineral reflects light

Give three examples each of native metals and native non-metals

Gold (Au)
Silver (Ag
Copper (Cu)

Diamond (C)
Graphite (C)
Sulfur (S)

What's the difference between a halogen and a halide?

halogens are a specific group of elements in group 17 of the periodic table, while halides are the compounds or salts formed by the halogens combining with other elements.

What is the best example of "the eye will see what the mind is prepared to find"?

D.
a) Knowing how to properly use your tools to conduct a hardness test.
b) Understanding that crystal structure is an essential aspect of something being a mineral species.
c) Having your wits about you so you remember to actually conduct the physical test.
d) Studying up on the physical properties of a new mineral prior to conducting fieldwork.

What does it mean for a mineral to have adiagnostic physical property?

D

a) A physical property that every specimen of that particular mineral species displays
b) A physical property that is unique solely to that mineral species
c) A unique set of physical properties that only a certain mineral species contains
d) A physical property that is highly suggestive of acertain mineral species, but by itself not necessarily unique to that mineral nor alwayspresent

Amygdaloidal aggregate habit is best associated with

B

a) compact or 'massive' habits
b) volcanic rocks
c) plutonic igneous rocks
d) metamorphic minerals
e) all of the above

Asbestos is

B

a) a mineral species
b) a collection of mineral species
c) an aggregate habit
d) always a type of serpentine mineral
e) all of the above

what is a habit often shown by silver or copper. (kinda looks branchy)

hackly