Minerals to know• Calcite
• Fluorite
• Galena
• Kaolinite
• Halite
• Copper
• Talc
• Graphite
• Bornite
• Pyrite
• Garnet*
• Kyanite*
• Staurolite*
• Mica– Biotite
– Muscovite
– Lepidolite
• Gypsum– Satin Spar
– Selenite
• Feldspar– Pink
– Others
• Quartz– Crystal
– Chert
– Rose
– Citrine
– Milky
– Smokey
– Amethyst
• Hematite– Massive
– Micaceous
Mineral Families
*New for 2017
Mineral Properties
• Color
• Streak
• Luster
• Hardness
• Density
• Crystal Shape
• Cleavage
• Fracture
• Fluorescence
• Reaction to Acid
Calcite 2A• Color- all colors possible
• Streak- White
• Luster- Vitreous, Pearly, Waxy,
Greasy
• Hardness- 3.0 (the 3 on the
Mohs scale
• Density- 2.7g/cm3
Vitreous Pearly
WaxyWhite streak Greasy
Calcite 2ACleavage- Rhombohedral,
3 directions none at 90° Dog Tooth Crystal
Nail Head Crystal
Rhombohedral Crystal
Rhombohedral Cleavage
Conchoidal Fracture
Fracture
Conchoidal
(Rarely
observed)
Crystal Shape
Dogtooth,
Rhombohedral
Nail head
Calcite 2A
• Sometimes Fluorescent
• Displays Double Refraction
• Reacts to Acid
Double Refraction
Fluorescence
Reacting with acid
Galena 4A• Color- Silver or Gray
• Streak- Gray
• Luster- Metallic bright or dull
• Hardness- 2.5
• Density- 7.5g/cm3
Gray streak
Galena 4A
Cleavage- Cubic,
3 directions all 90°
Crystal Shape-
Cubes and
Octahedrons
are commonOctahedral Crystals
Cubic Crystals
Cubic Cleavage
Fracture- rarely
observed,
usually breaks
on cleavage
Galena 4A•Galena is an ore of
lead
•Lead is very heavy,
but it is toxic
•We use lead as
weights, and in
bullets
•We used to use
lead in gasoline and
paint
Lead Paint
Bullets
Sinkers
Leaded Gasoline
Lead
Quartz Family• Color- Many colors
• Streak- White
(harder than streak plate)
• Luster- Vitreous, Greasy
• Hardness- 7.0
(the 7 on the Mohs scale)
• Density- 2.6g/cm3
White streak
Greasy
Vitreous
Quartz Family
• Crystal Shape-
Hexagonal (6
sides)
• Cleavage- No
cleavage
• Fracture-
Conchoidal or
uneven
Hexagonal Crystals
Conchoidal FractureUneven Fracture
Quartz Family
• Crystal Shape-
Hexagonal (6
sides)
• Cleavage- No
cleavage
• Fracture-
Conchoidal or
uneven
• Piezoelectric
Lab Grown Quartz
Hexagonal Crystals
Conchoidal Fracture
Quartz Family
Quartz Crystal- Clear
Citrine- yellow,
orange, brown
Amethyst- Purple
Smokey Quartz-
Black, Gray
Milky Quartz-
Opaque White
Chert- Opaque,
Many colors
Fine grained
Rose Quartz- Pink
Quartz FamilyTourmalated Quartz-
Quartz Crystal with
tourmaline inclusions
Quartz is used for
gemstones
Rutilated Quartz-
Quartz Crystal with
rutile inclusions
Cinnamon Quartz-
Quartz Crystal with
Hematite inclusions
Graphite 15A• Color- Black, Grey, Silver
• Streak- Silvery-Black
• Luster- Earthy, Metallic
• Hardness- 1-2
• Density- 2.1g/cm3
Silver-Black streak
Graphite 15A
Cleavage- Basal,
1 Direction
Crystal Shape-
Hexagonal,
OctahedralOctahedral Crystal
Uneven Fracture
Basal Cleavage
Fracture-
Uneven
Hexagonal Crystal
Graphite 15A
Graphite has a layer of loose
atomic bonds
This makes it very soft and
slippery
Its dark color
and softness
are perfect for
lead pencils
The weak
atomic bonds
make graphite
an excellent
lubricator
Mica Family• Color- Many colors
• Streak- White
• Luster- Pearly,
• Hardness- 2.5
• Density- 2.8g/cm3
White streak
Mica Family
Cleavage- Basal,
1 Direction, perfect
Crystal Shape-
Hexagonal,
Bladed, Rose
Bladed Mica
Basal Cleavage
Fracture- Uneven,
rarely observed
Hexagonal Crystal
Mica Rose
Mica Family
Biotite 1A Muscovite 9 Lepidolite 10
Mica Family•Mica is an excellent insulator of heat
and electricity
•It is used in toasters and electronics to
contain and direct heat
•It has been used as windows, and is
still sometimes used in stove windows
•It is very sparkly when ground, so it is
used as a type of glitter
Fluorite 3A• Color- all colors
possible• Streak- White
• Luster- Vitreous,
Greasy
• Hardness- 4.0 (the 4
• on the Mohs scale)
• Density- 3.2g/cm3
White streak
Fluorite 3AUneven Fracture Octahedral Cleavage Octahedral Crystal Cubic Crystal
Fluorite 3AUsed:
•As an additive in glass and
enamels
•To make special lenses
•To make hydrofluoric acid
•As a flux to help smelt metals
Lenses
GlassEnamel
Acid
Flux
Fluorite 3A
Gypsum family 5A&11• Color- many colors
possible• Streak- White
• Luster- vitreous, silky, pearly, greasy, dull
• Hardness- 2.0 (the 2 on the Mohs scale
• Density- 2.3g/cm3
White streak
Gypsum family 5A&11• Crystal Shape-
Monoclinic,
often bladed or elongated
• Cleavage-Rhombohedral, 3 directions
(1 good, 2 poor) none at 90°
• Fracture-splintery
• Slightly soluble in water
Bladed Rose
Splintery FractureRhombohedral Cleavage
Elongated Monoclinic
Gypsum family 5A&11Massive
Selenite
Fishtail
Rose
Satin Spar
Gypsum family 5A&11Uses-
•Plaster
•Drywall
•Fertilizer
•Cement
•Carvings
Hematite family• Color- red, black,
grey, silver
• Streak- bright to
dark red
• Luster- Metallic to
submetellic
• Hardness- 5.5-6.5
• Density- 5.3g/cm3
Dark-Light
Red Streak
Hematite family• Crystal Shape-
hexagonal,
botryoidal,
roses
• Cleavage-
none
• Fracture-
uneven,
splintery,
earthy
Bladed Rose Botryoidal
Massive Micaceous Hexagonal
Splintery
Hematite family
•Hematite is mined
in Michigan
•It can be used to
make iron and steel
•It is also used to
make jewelry
Pyrite 14A• Color- yellow brassy gold
• Streak- greenish black
• Luster- Metallic Bright or dull
• Hardness- 6
• Density- 5.0g/cm3
Greenish-Black streak
Pyrite 14A• Crystal
Shape-
cubic,
octahedral,
Pyritohedron
dollar/sun
• Cleavage-
Poor
• Fracture-
conchoidal,
uneven
Conchoidal fracture
Cubes Octahedrons Dollar/Sun
Pyritohedron Massive
Pyrite 14A
Ore of Real Gold
Used to make paper
processing chemicals
Old “Crystal Radios”
sometimes used
pyrite crystals
Used to
make
Sulfuric Acid
Sparks when hit on steel
Copper 10A• Color- reddish, oxidizes green
• Streak- red
• Luster- Metallic Bright or dull
• Hardness- 2.5
• Density- 8.9g/cm3
Red streak (Bottom)
Copper 11AOctahedral Crystal Wire-Like
Hackly Fracture Dendritic shape “Float” Copper
Cubic Crystal
No Cleavage
Copper 11AUsed in wires- big
to small, coins,
pipes, roofs and
household items
and much more
Feldspar Family 8A• Color- many colors possible• K Potassium is pink• Streak- White
• Luster- Vitreous, pearly
• Hardness- 6.0 (the 6 on the
Mohs scale)
• Density- 2.6g/cm3
White streak
Feldspar Family 8A• Crystal
Shape-
Triclinic,
monoclinic,
tabular
• Cleavage-
Two or three
planes
• Fracture-
uneven,
uncommon
Feldspar Family 8A
Used in making glass, ceramic, paint, plastic, and rubber
Kaolinite 7A• Color- White to off white• Streak- White
• Luster- Earthy
• Hardness- 2
• Density- 2.5g/cm3
• No visible Crystals
• Basal cleavage
White streak
Kaolinite 7AUses- glass,
ceramic, cosmetics,
toothpaste, light
bulbs, paint, plastic,
rubber
Kaolinite is made from
weathered feldspars
Halite 9A• Color- often clear or white,
many colors possible• Streak- White
• Luster- Greasy, vitreous, silky,
• Hardness- 2.0
• Density- 2.2g/cm3
White streak
Halite 9A• Crystal Shape-
cubic, massive fibrous
• Cleavage- cubic, all at 90°
• Fracture- Rarely Conchoidal, splintery
• Soluble in water
Cubic Cleavage
Cubic Crystals
Splintery Fracture
Rare
Halite 9A
Halite 9A
Talc 11A• Color- white, green, brown• Streak- White
• Luster- waxy, pearly, greasy
• Hardness- 1.0 (the 1 on the Mohs scale)
• Density- 2.7g/cm3
White streak
Talc 11A• Shape-
foliated
massive
• Cleavage-
Basal, 1
direction
• Fracture-
uneven,
splintery
Talc 11AUses- Baby powder, paper,
electric insulators, carvings,
ceramic, cosmetics,
toothpaste, plastic, rubber
Bornite• Color- Many colors
• Streak- Grayish black
• Luster- Metallic
• Hardness- 3
• Density- 5.0g/cm3
Grayish-Black streak
BorniteFreshly broken faces are often yellowishWith heat or time the faces oxidize many iridescent colors,
eventually turning nearly black
•Usually massive, rarely
octahedral crystals
•No cleavage
•Sometimes shows
conchoidal fracture
•Nicknamed
“Peacock Copper”
•Ore of Copper
Garnet (family)• Color- Reddish/browinsh
common, all colors possible
• Streak- White
• Luster- Vitreous to Resinous
• Hardness- 6.5-7.5
• Density- 3-4g/cm3
White streak
Garnet• Crystal Shape-
Rhombic dodecahedron or cubic
• Cleavage-indistinct
• Fracture-Conchoidal to uneven
• Slightly attracted to strong magnet
Garnet• Garnet in
metamorphic rocks can indicate temperature and pressure that the rock endured
• Garnet is used a gemstone
• It is January’s birthstone
• Garnet is used as an abrasive
Kyanite• Color- blue & white common,
many colors possible
• Streak- White
• Luster- Vitreous to Pearly
• Hardness- 4.5-5 with grain,
6.5-7 against the grain
• Density- 3-4g/cm3
White streak
Kyanite• Kyanite in
metamorphic rocks can indicate temperature and pressure that the rock endured
• Kyanite is used a gemstone
• Kyanite is used as an electrical and temperature insulator
Staurolite• Color- Reddish- Brownish-
Blackish
• Streak- White
• Luster- Dull, Resinous
• Hardness- 7-7.5
• Density- 3.8g/cm3
White streak
Staurolite
• Crystal Shape-Monoclinic
• Often found twinned at 60o occasionally twinned at 90o
• Cleavage- One direction
• Fracture- Subconchoidal
• Kyanite in metamorphic rocks can indicate temperature and pressure that the rock endured
Designing a Chart
• I recommend making a spreadsheet for organizing rock and mineral properties
Yours
might look
something
like this
Rock properties to be sure you cover
Igneous rocks
• Mineral
composition
• Intrusive/
extrusive
• Magma type
• Crystal size
• Vesicles
• Uses
Sedimentary rocks
• Mineral
composition
• Type (Clastic, etc)
• Grain size
• Grain sorting
• Fissile/non
• Clues to past
environments
• Fossils
• Uses
Metamorphic
rocks
• Mineral
composition
• Grade
(High/low)
• Possible
parent rocks
• Foliated/non
• Uses
Mineral properties to
be sure you cover
• Color
• Streak
• Luster
• Hardness
• Density (S.G.)
• Crystal shapes
• Cleavage
• Fracture
• Special properties
• Uses
