L7-9 minerals

Question 1

Criteria for a mineral

Answer 1

1. naturally occurring
2. inorganic (dicey)
3. SOLID (specific crystalline structure)
4. CONSISTENT CHEMICAL COMPOSITION

Question 2

Atom bonds within minerals and lattice influence on mineral properties

Answer 2

Minerals must have a crystalline structure. atoms form a repeating pattern known as a lattice

Ionic: polar soluble (NaCl, halite)
Covalent: strong and hard. not soluble. crumbly (C, diamond)
Metallic: good conductors. ductile and malleable (native Cu, copper and Au, gold)
Van der Waals: weakest bond (C, graphite)

Question 3

Categories of minerals defined by anions or anionic groups.

Answer 3

Native minerals: composed of only one element
gold
silver
copper
Oxides: metal bound to O
hematite
magnetite
curundum
bauxite
limonite
Carbonates: metal bound to CO3
calcite
siderite
magnesite
malachite
azurite
Sulphides: metal bound to S
galena
molybdenite
pyrite
bornite
Silicates: metal bound to SiO2

Question 4

Configurations of silica tetrahedra found in silicate minerals

Answer 4

Isolated silica tetrahedra
Chains of linked silica tetrahedra
Sheets of linked silica tetrahedra
Networks of linked silica tetrahedra

Question 5

Ways minerals form.

Answer 5

Crystallization of magma

Metamorphism: solid minerals react with each other under high pressures and temperatures, and new minerals are formed

Weathering: minerals unstable at Earth’s surface are chemically altered by surface processes

Precipitation from a solution

Organic formation: organisms build shells (primarily of calcite or aragonite), and teeth and bones (primarily of apatite)

Question 6

Describe the trend in mineral diversity over the course of earths history

Answer 6

Diversity of minerals has increased over time from about a dozen 4.6 billion years ago to >5600 today

Question 7

Properties of minerals

Answer 7

Colour, streak, lustre, hardness, crystal habit, cleavage/fracture, and density

Question 8

Cause of mineral properties

Answer 8

Composition and structure