List 00 - Diagnostic Features

Question 1

Quartz

Answer 1

7 hardness, Vitreous luster, White streak

Question 2

Biotite

Answer 2

One perfect cleavage, 2.5 to 3 hardness, Pearly luster

Question 3

Muscovite

Answer 3

One perfect cleavage, 2 to 2.5 hardness, Pearly luster

Question 4

Talc

Answer 4

1 hardness, White streak, Greasy luster

Question 5

Calcite

Answer 5

Reacts w/ acid, 3 hardness, white streak

Question 6

Dolomite

Answer 6

Reacts w/ acid when powdered, 3.5 to 4 hardness, white streak

Question 7

Pyroxene

Answer 7

5 to 6 hardness, Vitreous luster, White/Greenish-white/Gray streak, Nearly right angle cleavage

Question 8

Amphibole

Answer 8

5 to 6 hardness, Vitreous luster, White to Gray streak,, Cleavages meeting at 56 and 124 degrees

Question 9

Olivine

Answer 9

6.5 to 7 hardness, Vitreous luster, White streak, Poor 90 deg. cleavage

Question 10

Feldspar

Answer 10

6 hardness, blocky crystal habit, 2 cleavages meeting at nearly right angles

Question 11

Magnetite

Answer 11

Magnetic, 5.5 to 6.5 hardness, metallic to dull luster, black streak, no cleavage

Question 12

Hematite

Answer 12

5 to 6 hardness, No cleavage, Metallic to dull luster, red/brown streak

Question 13

Illmenite

Answer 13

5 to 6 hardness, Metallic luster, Hexagonal

Question 14

Pyrite

Answer 14

6 to 6.5 Hardness, Brittle, No cleavage, Conchoidal fracture, Metallic luster, Greenish-black to Brownish-black streak

Question 15

Galena

Answer 15

2.5 Hardness, 3 Perfect cleavage (cubes), Metallic, Lead gray streak

Question 16

Gypsum

Answer 16

2 Hardness, Vitreous to Pearly luster, 1 Good cleavage, White streak

Question 17

Apatite

Answer 17

5 Hardness, White streak, Hexagonal, Vitreous luster

Question 18

Fluorite

Answer 18

4 Hardness, Vitreous luster, 4 Perfect cleavages (Cubes break to octahedrons), White streak

Question 19

Halite

Answer 19

Tastes salty, 2.5 Hardness, Vitreous luster, 3 Perfect cleavages at right angles (cubes), White streak

Question 20

Staurolite

Answer 20

7 to 7.5 Hardness, Distinctive cross-shaped penetration twins, Vitreous to Dull luster

Question 21

Kyanite

Answer 21

Vitreous luster, 5.5 to 7 Hardness, No streak

Question 22

Sillimanite

Answer 22

6.5 to 7.5 Hardness, Vitreous to Silky luster, No streak, Transparent to translucent

Question 23

Garnet

Answer 23

6.5 to 7.5 Hardness, Vitreous to resinous luster, White streak, No cleavage