Thin Sections

Question 1

Answer 1

Actinolite

[extremely similar to tremolite]

Question 2

Answer 2

Alkali Feldspar

Question 3

Answer 3

Amphibole

Question 4

Answer 4

Biotite

Question 5

Answer 5

Calcite

Question 6

Answer 6

Chlorite

Question 7

Answer 7

Clinozoisite

Question 8

Answer 8

Cordierite

[creates hexagonal extinction umbrellas in CPO]

Question 9

Answer 9

Diopside

Question 10

Answer 10

Epidote

Question 11

Answer 11

Garnet

[always extinct in CPO (may appear as granules)]

Question 12

Answer 12

Hornblende

[may appear as green, light blue, or brown]

Question 13

Answer 13

Kyanite

Question 14

Answer 14

Microcline

Question 15

Answer 15

Muscovite

[with bitotite inclusions]

Question 16

Answer 16

Olivine

Question 17

Answer 17

Plagioclase

Question 18

Answer 18

Pyroxene

Question 19

Answer 19

Quartz

[no interference colors]

Question 20

Answer 20

Scapolite

[poor reference image, appears as quartz but with extreme interference colors]

Question 21

Answer 21

Sillimanite

Question 22

Answer 22

Spinel

Question 23

Answer 23

Staurolite

[usually breaks off at sharp at angles, may be fragmented with rounded inclusions of other minerals, occasionally forms diamond shaped fragments similar to titanite]

Question 24

Answer 24

Titanite

[always forms diamond shaped fragments of high relief]

Question 25

Answer 25

Tourmaline

[can be discerned by c-axis cross sections, display blue to pink pleochroism, usually green]

Question 26

Answer 26

Tremolite

[extremely similar to actinolite]