Geology 1403 Lab Exam 1

Biotite (Mica)

Dark colored
Streak: White to gray
Luster: Vitreous
Hardness: 2.5-3
Cleavage: 1 Plane
Other Properties: Thin Sheats

Calcite

Variable to clear
Streak: White to gray
Luster: Vitreous to Earthy
Hardness: 3
Cleavage: 3 Planes (perfect) - rhombohedral
Other Properties: Reacts with HCL acid

Copper

Copper
Streak: Copper
Luster: Metallic / Dull
Hardness: 2.5 -3
Cleavage: None
Other Properties: Tarnishes brown or green

Corundum

Red- gray to brown or gray
Streak: White
Luster: Dull
Hardness: 9
Cleavage: None
Other Properties: Hexagonal Crystals

Fluorite

Variable Color
Streak: White
Luster: Vitreous (Clear)
Hardness:4
Cleavage: 4 Planes (Octahedral)
Other Properties: Used in Toothpaste

Galena

Shiny Silver Gray or Dull Gray
Streak: Gray - Dark Gray
Luster: Metallic
Hardness: 2.5
Cleavage: 3 Planes at 90 (Cubic)
Other Properties: High Specific Gravity

Gypsum

White, Clear, Variable
Streak: White
Luster: Vitreous
Hardness: 2
Cleavage: No Cleavage or 1 plane
Other Properties: None

Halite

Clear to gray yellow to red
Streak: White
Luster: Vitreous
Hardness: 2.5
Cleavage: 3 Planes at 90 (PERFECT)
Other Properties: SALTY

Hematite (Specular)

Steel Gray
Streak: RED
Luster: Metallic
Hardness: 5-6
Cleavage: None
Other Properties: 2 forms

Hematite (Earthy)

Red
Streak: RED
Luster: Dull
Hardness: 1.5 -3
Cleavage: None
Other Properties: 2 forms

Hornblende (Amphibole)

Dark Greek to Black
Streak: White
Luster: Vitreous
Hardness: 5 -6
Cleavage: 2 planes 56-124
Other Properties: None

Kaolinite (Clay)

White, Dirty White
Streak: white
Luster: Dull
Hardness: 2 - 2.7
Cleavage: No Apparent (too soft)
Other Properties: Earthy Smell

Limonite

Yellow
Streak: Yellow - brown
Luster: Dull (Earthy)
Hardness: 1.5 - 5.5
Cleavage: None
Other Properties: None

Magnetite

Dark Gray - Black
Streak: Dark Gray
Luster: Metallic
Hardness: 6
Cleavage: None Apparent
Other Properties: MAGNETIC

Muscovite (Mica)

White to clear silver
Streak: White
Luster: Vitreous
Hardness: 2.5 - 3
Cleavage: 1 plane - sheets
Other Properties: THIN SHEETS

Olivine

Green to Dark Green
Streak: White to shades of green
Luster: Vitreous
Hardness: 6.5 -7
Cleavage: Indistinct / None
Other Properties: Granular or grainy

Potassium Feldspar

L. color, white, cream, pink
Streak: white
Luster: Vitreous
Hardness: 6
Cleavage: 2 planes nearly 90
Other Properties: Pink variety is common

Plagioclase Feldspar

L. color variable
Streak: White
Luster: Vitreous
Hardness: 6 - 6.5
Cleavage: 2 planes nearly 90
Other Properties: Striations

Pyrite

Brass Yellow
Streak: Black, dark green, brown black
Luster: Metallic
Hardness: 6 - 6.5
Cleavage: None - FRACTURE
Other Properties: Cubic crystals with striations (Fool's Gold)

Pyroxene (Augite)

Dark Green to Black
Streak: white to gray
Luster: Vitreous
Hardness: 5.5 - 6
Cleavage: 2 planes of nearly 90
Other Properties: None

Quartz

Variable L & D
Streak: None
Luster: Vitreous / Shiny
Hardness: 7
Cleavage: Conchoidal - FRACTURE
Other Properties: Scratches Glass

Sphalerite

Bronze to Yellow - Brown
Streak: White to pale, yellow - brown
Luster: Vitreous (cleavage face) to Metallic (crystal faces)
Hardness: 3.5 - 4
Cleavage: Excellent
Other Properties: Rotten Egg Smell, 2 Lusters

Sulfur

Yellow to Red
Streak: Pale Yellow
Luster: None
Hardness: 1.5 - 2.1
Cleavage: None
Other Properties: Rotten Egg Smell

Talc

Gray to light green
Streak: White
Luster: Pearly, greasy, or dull
Hardness: 1
Cleavage: No cleavage
Other Properties: Soapy Feel

Granite

Origin: Instrusive, slow cooling
Texture: Phaneritic
Composition: Felsic

Diorite

Origin: Intrusive, slow cooling
Texture: Phaneritic
Composition: Intermediate

Gabbro

Origin: Instrusive, slow cooling
Texture: Phaneritic
Composition: Mafic

Peridotite

Origin: Instrusive, slow cooling
Texture: Phaneritic
Composition: Ultramafic

Rhyolite

Origin: extrusive, rapid cooling
Texture: Aphanitic
Composition: Felsic

Andesite

Origin: Extrusive, Rapid Cooling
Texture: Aphanitic
Composition: Intermediate

Basalt

Origin: Extrusive, Rapid Cooling
Texture: aphantic
Composition: Mafic

Obsidian

Origin: Extrusive Rapid Cooling
Texture: Glassy
Compostion: Minerals had no time to form

Pumice

origin: Extrusive Rapid Cooling
Texture: Vesicular
Composition: Felsic and Intermediate

Vesicular Basalt

Origin: Extrusive, Rapid Cooling
Texture: Vesicular
Composition: Mafic

Volcanic Tuff

Origin: Extrusive, Rapid Cooling
Texture: Pyroclastic
Composition: fragments of Tephra

Shale

Composition: Clay
Type: Detrital; Mud, round
Sorting: Well

Arkosic Sandstone

Composition: Rock Fragments or mineral grains
Type: Detrital; Gravel, round
Sorting: Moderate

Quartz Sandstone

Composition: Sand
Type: Detrital; Sand, round
Sorting: Well

Lithic Sandstone

Composition: Rock Fragments
Type: Detrital; Sand, round
Sorting: Well

Conglomerate

Composition: Rock fragments and mineral grains
Type: Detrital; Gravel, rounded
Sorting: Moderate to poor

Breccia

Composition: Rock Fragments and mineral grains
Type: Detrital; Gravel, Angular
Sorting: Poor

Rock Salt

Composition: Halite
Type: Chemical(inorganic)
Info: Softer than glass, salty taste

Rock Gypsum

Composition: gypsum
Type: Chemical(inorganic)
Info: Softer than finger nail, sugary look

Oolitic Limestone

Composition: Calcite; spherical grains(ooids)
Type: Chemical(inorganic)
Info: Easy to tell

Chert

Composition: Quartz
Type: Chemical(inorganic)
Info: Conchoidal Fracture, harder than glass

Peat

Composition: Plant Fragments
Type: Biochemical(organic)
Info: visible plant remains, first stage of coal

Lignite

Bituminous Coal

Composition : Carbonized Plant Fragments
Type: Biochemical(Organic)
Info: Black to dark brown; brittle; sooty; light in mass

Micrite Limestone

Chalk

Composition: Calcite(limestone)
Type: Biochemical(organic)
Info: Microscopic shells, powdery Reacts with HCl!!!!

Coquina

Composition: Calcite(Limestone)
Type: Biochemical(organic)
Info: Well sorted hash of shell fragments, porous, little visible matrix or cement

Fossiliferous Limestone

Composition: Calcite(Limestone)
Type: Biochemical(organic)
Info: Fossilized shell in a fine grain matrix

Slate

Luster:dull
Cleavage: 1 direction(salty rock cleavage)
Info: Rings when tapped with a nail, foliated

Phyllite

Luster: Satiny
Cleavage: Breaks along wrinkled or foliated planes
Info: small micaceous minerals barely visible, foliated

Schist

Luster: Platy minerals?
Cleavage: along scaly foliation
Info: possible in many mineral varieties

Gneiss

Luster: Dull
Cleavage: ?
Info: Genissic Banding along light and dark mineral bands

Anthracite Coal

Luster: Shiny
Cleavage: Fracture
info: black, made of Carbon

Marble

Luster: Satiny?
Info: Reacts with acid; softer than glass; many color varieties

Quartzite

Luster: Shiny
Info: grains not rub off like sandstone, harder than glass

Serpentinite

Luster: dull Metamorphic, non-foliated