1. Mineral Identification

2. Identify what mineral is being described in each question below
Identify what mineral is being described in each question below. Explain how you knew (For example, which property or properties did you look at).

3. Uses and other properties
A student finds a black mineral that breaks into sheets easily and is relatively soft.
Low hardness
cleavage
Mineral
Colour(s)
Streak
Hardness
Breakage pattern
Uses and other properties
calcite
colourless, white, pale blue
colourless,
white 3
cleavage in three directions
fizzes when HCI is added
used in cements and other building materials
feldspar
colourless, white to grey, green
colourless 6
two cleavage planes, meeting at ~90° angle
used in the manufacture of ceramics
quartz
various colours
none 7
conchoidal fracture
used as gemstones and in glass manufacture, electronic equipment, radios, computers, and watches
graphite
black to grey
1-1.5
basal cleavage (scales)
used as pencil lead, lubricants for locks, rods to control some small nuclear reactions, and battery poles
galena
grey
grey to black
2.5
perfect cubic cleavage
source of leads
used in pipes, shields for X-rays
hematite
black, reddish brown
reddish brown
irregular
fracture
source of iron
converted to “pig” iron and made into steel
pyrite
light, brassy yellow
greenish black
6-6.5
uneven fracture
sources of iron
called “fool’s gold”

4. 1b)A student tries to break a mineral apart with their fingernail but is unsuccessful. Using a hammer, they find that it breaks into jagged pieces and leaves a mostly black streak on a ceramic tile
Answer: Pyrite (hardness, streak, fracture)

5. 1c) A black mineral leaves a red streak on a streak plate
1c) A black mineral leaves a red streak on a streak plate. When you attempt to break it into pieces it breaks into jagged pieces.
Answer: hematite (color, streak, fracture)

6. 1d) A pink mineral leaves a colorless streak and cannot be scratched by glass.
Answer: quartz – streak, hardness, color

7. 2) A student finds a colorless mineral but can’t decide whether it is calcite, feldspar or quartz. What one test should she perform to help you figure out which one it is? (Hint: use the chart from the question above to help you answer this
Answer: hardness