Minerals

Question 1

Amphiboles( aka hornblende)

Answer 1

-metamorphic rock
-mohs hardness 6
-2 cleavage directions(60 and 120 degrees)
-vitreous lustre
-6 sided crystal
-3.35 specific gravity
-colour: BLACK, dark green, brown
-stepped cleavage faces

Question 2

Biotite

Answer 2

-Cleavage 1 direction
-Hardness: 2.5-3
-Black to brownish colour
-specific gravity: 2.8-3.2
vitreous lustre
-perfect cleavage
-a mica (sheet)

Question 3

Calcite

Answer 3

-Cleavage 3 directions
-Hardness: 3
-colourless, white, grey, or pinkish
-specific gravity: 2.8
*reacts with HCL
-perfect cleavages at 75 degrees (rhombic)
-double refraction
-transparent to opaque
-vitreous lustre

Question 4

Chalcopyrite

Answer 4

-metallic lustre
-streak is black, greenish, or gray
-hardness: 3.5-4
-golden yellow colour
-no cleavage
-specific gravity: 4.2
-massive size

Question 5

Dolomite

Answer 5

-cleavage in 3 directions
-hardness: 3.5-4
-colourless, white, grey, pinkish
-specific gravity: 2.8
-small rhombic crystals or massive
-cleavages at 75 degrees
-reacts slowly with HCL unless powered
-vitreous lustre

Question 6

Galena

Answer 6

-black, greenish, or grey streak
-hardness: 2.5
-silver-gray colour
-metallic lustre
-3 perfect cubic cleavage
-specific gravity: 7.5
-cubic crystals common

Question 7

Gypsum

Answer 7

-cleavage in 3 directions
-hardness: 2
-white colour or colourless
-specific gravity: 2.3
-tabular, massive, or fibrous
-vitreous to silky lustre
-1 perfect with 2 poor to good cleavages at 75-90 degrees

Question 8

Halite

Answer 8

-cleavage in 3 directions
-hardness: 2-2.5
-colourless or white
-specific gravity: 2
-soluble in water
-salty taste
-perfect cleavages at 90
-cubic
-vitreous, sometimes dull lustre

Question 9

Magnetite

Answer 9

-black coloured streak
-hardness: 6
-dark grey to black
-no cleavage
-specific gravity: 5.2
-dull on non-fresh surface
-usually octahedral
*attracted to magnet

Question 10

Muscovite

Answer 10

-cleavage in 1 direction
-hardness: 2-3
-colourless to light brown
-specific gravity: 2.8
-thin, flexible sheets
-transparent
-vitreous lustre
-perfect cleavage
-a mica

Question 11

Olivine

Answer 11

-No cleavage
-hardness: 6.5-7.5
-olive green colour
-specific gravity: 3.5-4.5
-vitreous to dull luster
-commonly occurs as small grain
-transparent to translucent

Question 12

Plagioclase Feldspar

Answer 12

-cleavage in 2 directions
-hardness: 6
-gray to gray-blue colour or white colour
-specific gravity: 2.6-2.8
-2 good cleavages at 90 degrees
-lamellar twinning on some sides when light is reflected
-vitreous lustre

Question 13

Potassium Feldspar

Answer 13

-cleavage in 2 directions
-hardness: 6
-salmon pink - white colour
-specific gravity: 2.5-2.6
-2 good cleavages at about 90 degrees
-light dark banning common
-vitreous listre

Question 14

Pyrite

Answer 14

-greenish black streak
-hardness: 6-6.5
-brass- yellow colour
-no cleavage
-specific gravity: 5
-cubic habit or massive

Question 15

Pyroxene

Answer 15

-cleavage in 2 directions
-hardness: 6
-dark green to black colour
-specific gravity: 3.5
-short
-prismatic 8 sided crystal
-vitreous to dull lustre
-2 imperfect cleavages at 90 degrees

Question 16

Quartz

Answer 16

-no cleavage
-hardness: 7
colourless, milky, purple, gray, pink
-specific gravity: 2.7
-conchoidal fracture
-transparent to translucent

Question 17

Sphalerite

Answer 17

-6 perfect dodecahedal cleavage
-streak yellow
-hardness: 3.5-4
-colour: brown to yellow or black
-specific gravity: 4
-resinous lustre

Question 18

Sylvite

Answer 18

-cleavage in 3 directions
-hardness: 2.5
-colour: orange/salmon
-specific gravity: 2
-soluble in water
-bitter taste
-cleavages at 90 degrees( cubic)

Question 19

Andalusite

Answer 19

-cleavage in 2 directions
-hardness: 7.5
-colour: brown, white, pink, green
-specific gravity: 3.15
-long, prismatic crystals with 4 sided cross section
-dark coloured cross-shaped (cruciform inclusions)
-2 good cleavages at 90 degrees

Question 20

Garnet

Answer 20

-no cleavage directions
-hardness: 7-7.5
-red-burgundy brown or yellow
-specific gravity: 3.5-4.5
conchoidal fracture
-occurs in well formed 12 sided crystals (dodecahedral)

Question 21

Kyanite

Answer 21

-cleavage in 1 direction
-hardness: 4-7
-light blue to greenish blue
-specific gravity 2.8
-hardness of 4 parallel to long direction of crystal and 7 across crystal
-bladed

Question 22

Serpentine

Answer 22

-no cleavage
-hardness: 3-5
-green, gray, black, often multicoloured
-specific gravity 2.5-2.6
-greasy lustre
-slightly greasy feel
-massive to fibrous

Question 23

Staurolite

Answer 23

-no cleavage directions
-hardness: 7-7.5
-red-brown to brownish black colour
-specific gravity: 3.7
-prismatic and cross-shaped (cruciform)
-hexagonal cross section

Question 24

Talc

Answer 24

-cleavage in 1 direction
-hardness: 1-2
-white, light apple green colour
-specific gravity: 2.7-2.8
-soapy feel
-light gray streak
-pearly or greasy lustre