Mdl

Question 1

What are rocks defined as?

Answer 1

An aggregate of minerals and silicates predominantly found in the solid state of matter.

Question 2

How are rocks categorized?

Answer 2

Rocks are split into separate categories that define the way they were formed.

Question 3

What are minerals?

Answer 3

Naturally occurring substances made from geological processes.

Question 4

What are the characteristics of minerals?

Answer 4

1. A mineral is a naturally occurring substance.
2. A mineral is inorganic.
3. A mineral is a homogenous solid.
4. A mineral has a definite chemical composition.

For example, feldspars are aluminosilicate minerals with the general formula AT408.

Question 5

What is the definition of polymorphic minerals?

Answer 5

Minerals that share common chemical composition but with different crystalline structure.

Question 6

What are examples of polymorphic minerals?

Answer 6

Graphite and diamond.

Question 7

What does it mean for a mineral to have a crystalline structure?

Answer 7

The atoms in a mineral are arranged in a systematic and repeating pattern.

Question 8

How is the crystallinity of minerals determined?

Answer 8

Using X-ray diffraction (XRD) techniques.

Question 9

What are mineraloids?

Answer 9

Mineraloids have the characteristics of a mineral but without ordered internal structure.

Question 10

What are examples of mineraloids?

Answer 10

Opal, volcanic glass (obsidian), and polished quartz.

Question 11

How many different minerals are there approximately?

Answer 11

Approximately 4000 different minerals.

Question 12

What are physical properties used to identify minerals?

Answer 12

Color, Streak, and Luster.

Question 13

What is color in terms of identifying minerals?

Answer 13

The perceived wavelength of light that bounced off from the material and is detected by our eyes.

Question 14

What is streak in terms of identifying minerals?

Answer 14

The color of a crushed mineral’s powder.

Question 15

What is luster in terms of identifying minerals?

Answer 15

The behavior of light as it is reflected by the mineral.

Question 16

What is luster?

Answer 16

Luster is the surface appearance of a mineral. It can be metallic (pearly, waxy, vitreous or glassy, silky, adamantine or sparkly, dull or clay-like, and resinous or like resins)

Question 17

What is hardness?

Answer 17

Hardness is the resistance of a mineral to scratching. Friedrich Mohs developed the scale in 1812.

Question 18

What is the Mohs Hardness Scale?

Answer 18

The Mohs Hardness Scale is a scale developed by Friedrich Mohs to measure the hardness of minerals.

Question 19

What is cleavage?

Answer 19

Cleavage is the tendency of a mineral to break along particular directions at regions where the bonding is relatively weaker. It can be described as perfect, good, fair, or poor.

Question 20

What is fracture?

Answer 20

Fracture is when a mineral doesn’t have a planar cleavage.

Question 21

What is magnetism?

Answer 21

Magnetism is the tendency of a mineral such as magnetite, iron oxide (Fe3O4) to be attracted to a magnet.

Question 22

What is fluorescence?

Answer 22

Minerals with fluorescence like fluorite stop glowing.

Question 23

What is phosphorescence?

Answer 23

Minerals with phosphorescence can glow for a brief time after the light source is turned off.

Example minerals: calcite, celestite, colemanite, fluorite, sphalerite, and willemite

Question 24

What does effervescence describe?

Answer 24

Effervescence describes the reactivity of minerals to dilute hydrochloric acid (HCI).

Example minerals: calcite and dolomite

Question 25

What is the ‘acid test’ used for?

Answer 25

The ‘acid test’ is a diagnostic property of carbonate minerals such as calcite and dolomite. Bubbles form when calcite is exposed to a weak acid.

Question 26

What are some minerals that taste salty?

Answer 26

Some minerals taste salty such as Halite (rock salt, NaCl).

Question 27

What is an example of a mineral with a distinctive smell?

Answer 27

An example of a mineral with a distinctive smell is sulfur, which smells like rotten eggs.

Question 28

What is the study of rocks called?

Answer 28

The study of rocks is called petrology.

‘Petro’ means ‘rock’ and ‘logy’ means ‘study’

Question 29

What are the three types of rocks?

Answer 29

The three types of rocks are igneous, sedimentary, and metamorphic.