Week 1

Question 1

What is a mineral?

Answer 1

“A mineral is a naturally occurring solid with a highly ordered atomic arrangement and a definite (but not necessarily fixed) homogeneous chemical composition. It is usually formed by inorganic processes.”

Question 2

Mineral substances that are not mineral species include:

Answer 2

Mineral substances that are not mineral species include:
Rocks (consolidated composite materials)
Unconsolidated composites (soils, oozes, till, fault gouge…)
Natural glasses (volcanic, impact or friction melts)
Noncrystalline inorganic “mineraloids” like opal.
Noncrystalline organic “macerals” (e.g. “vitrinite” in coal)

Question 3

A mineral species is:

Answer 3

1) Naturally occurring
2) inorganic (usually)
3) hIghly ordered mineral arrangement
4) Solid

Question 4

Physical properties of minerals (interaction with light)

Answer 4

Lustre *
Colour *
Streak *
Play of colours
Chatoyancy & asterism
Luminescence

Question 5

Physical properties of minerals (mechanical)

Answer 5

Cleavage *
Parting 
Fracture *
Hardness *
Tenacity

Question 6

Crystal habits:

Answer 6

Crystal habits:
Euhedral: completely bounded by crystal faces, well-formed
Subhedral: partly bounded by crystal faces
Anhedral: lacks crystal faces (rounded or irregular surfaces)

Question 7

Interaction with light

Answer 7

Transparent: transmit light and through which an object may be seen.

Translucent: capable of transmitting light diffusely but is not transparent.

Opaque: does not transmit light, even on thin edges

Question 8

lustre

Answer 8

Metallic (polished metal surface, e.g. opaque minerals)

Non-metallic (minerals that transmit light)

Submetallic (in between)

Question 9

Colour

Answer 9

Mostly diagnostic of impurities
When colour reflects the presence of an essential element in the mineral, it can be diagnostic (e.g. sulphur = yellow, malachite = green, azurite = blue)

Question 10

Fracture

Answer 10

Conchoidal

Hackley

Question 11

Moh’s Scale of hardness

Answer 11

1) Talc
2) Gypsum
3) Calcite
4) Fluorite
5) Apatite
6) Orthoclase
7) quartz
8) topaz
9) Corundum
10) Diamond