Minerals Section 2

How many rating levels are there in the Mohs scale?

10

List 6 properties that are used to identify minerals: Clushs

CLUSHS; Cleavage / fracture, Luster, Unique characteristics, Streak, Hardness, Specific gravity

Hardness

Measure of how easily a mineral can be scratched

hardness is the measure of how easily a mineral can be scratched. what is the scale that compares mineral hardness?

Moh's scale

Essay question: Why is identifying a mineral by its color alone sometimes deceiving?

Other characteristics may be different, so they need to be considered,like the way a mineral breaks.The color of hematite for example can be red, gray, or silver, but its streak is always reddish brown. So color doesn't tell you enough information to identify the mineral.

Cleavage

Physical property of some minerals that causes them to break along smooth flat surfaces

Give examples of unique properties some minerals have.

Some glow under black light. magnetism (lodes stone and magnetite), fizzing (chemical reaction to HCL acid), light creates double image (calcite)

What is the hardest mineral listed on the Mohs scale and what is its rating?

The hardest mineral is Diamond, and its a 10 on the mohs scale.

If we calculate the ratio of a mineral's weight to the weight of an equal volume of water what number are we calculating?

The mineral's specific gravity. Like density.

What does the Mohs Scale compare ?

The mohs scale compares the hardness of minerals. It is possible to compare the hardness of common objects to the hardness of minerals using the Mohs scale

Streak

color of a mineral when it is in powdered form. Streak test is only useful for minerals softer than a streak plate.

Luster

describes the way a mineral; reflects light from its surface; can be metallic or non metallic

Which mineral can scratch anything?

diamond

which two minerals from this list can be used to scratch glass, and why? diamond, gypsum, apatite, quartz

diamond & quartz because they are the hardest, and are above glass on the mohs scale

list common objects in order from softest to hardest: fingernail, copper, iron nail, glass, steel file, streak plate

fingernail 2.5, copper 3, iron nail 4.5, glass 5.5, steel file 6.5, streak plate 7

Color

not enough to distinguish most minerals. Streak is more accurate.

Fracture

physical property of some minerals that causes them to break with uneven, rough, or jagged surfaces

Which element can scratch feldspar but not quartz?

steel file

List the minerals on the mohs scale from softest to hardest

talc, gypsum, calcite, fluorite, apatite, feldspar, quartz, topaz, corundum, diamond

which minerals can your fingernail scratch?

talk & gypsum

What is the softest mineral on the mohs scale and what is its rating?

the softest mineral is Talc, and its a 1 on the mohs scale.

True or false; color and appearance are not enough to distinguish most minerals

true