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