Minerals

Question 1

Mineral characteristics:

Answer 1

solid, inorganic (no C bonded to H), crystal structure, naturally occurring, all attempt to be electrically neutral, sometimes variable chemical composition

Question 2

Minerals are identified by:

Answer 2

• Colour
• Lustre
• Clarity
• Streak
• Habit
• Fracture
• Cleavage
• Hardness

Question 3

Earth minerals:

Answer 3

naturally occurring materials that makeup Earth’s crust

Question 4

Minerals make up a single:

Answer 4

crystal

Question 5

Most rocks consist of:

Answer 5

many minerals or fossils or soil

Question 6

All rocks are

Answer 6

solid aggregates of earth materials, earth materials become stuck together to form rock

Question 7

The physical properties of minerals are influenced by how the atoms:

Answer 7

in the crystal lattice are arranged and the types of bonds that hold the lattice together, also composition

Question 8

Both diamonds and graphite are minerals made of:

Answer 8

pure carbon, but arranged into different crystal structures

Question 9

Silicates contain:

Answer 9

SiO4 4-

Question 10

Native elements:

Answer 10

made of a single element

Question 11

Oxides contain:

Answer 11

O2 2-

Question 12

Sulfides contain:

Answer 12

S2-

Question 13

Sulfates contain:

Answer 13

SO4 2-

Question 14

Halides contain:

Answer 14

A halogen

Question 15

Carbonates contain:

Answer 15

CO3 2-

Question 16

> 90% of minerals contain:

Answer 16

Si and O in different combinations (b/c most abundant elements in the crust)

Question 17

The basic building block for most minerals is the:

Answer 17

silicate tetrahedron

Question 18

Silicate tetrahedron

Answer 18

• 4 oxygens atoms surround a single silicon atom
• Each oxygen atom covalently shares 1 electron with the silicon atom, jointly filling its outermost shell
• Bonds are very strong
• Overall charge is 4-

Question 19

All silicate minerals are assembled from different arrangements of tetrahedra

Answer 19

1. Neutralize their charge via forming ionic bonds with cations (ionic bonds are weaker than covalent)
2. Covalently bond adjacent tetrahedra together to neutralize
3. Both methods in different proportions
   - More oxygens shared = fewer cations needed to neutralize
   - Further diversity is achieved by changing the cations

Question 20

Cations of like size and charge can:

Answer 20

sub for one another within silicate structures of a single mineral

Question 21

The most commonly subbed cation pairs are:

Answer 21

• Fe2+/Mg2+
• Na+/Ca2+
• Al3+/Si4+

Question 22

Feldspars vary by:

Answer 22

double cation substitution

Question 23

Physical properties of silicate minerals are determined by:

Answer 23

• The composition of the mineral
• How atoms are arranged in the crystal lattice
• How atoms are bonded in the crystal lattice

Question 24

How do minerals form?

Answer 24

1. Solidification: new minerals crystallize directly out of molten rocks as they cool
2. Precipitation from a solution: new minerals precipitate directly out of a water solution (often due to evaporation)
3. Solid-state diffusion: rearrangement of atoms or ions through a solid to form a new crystal structure. Usually, result of increasing heat and pressure.
4. Biomineralization: living organisms produce minerals to strengthen their tissues i.e CaCO3 shells (still considered inorganic)
5. Precipitation from a gas: minerals crystallize directly from gas around geysers and volcanic vents. Gases cool as they enter the atmosphere, triggering crystallization