Mineral IDs

Question 1

olive is pale, flat, gives her relief, is a snake and cracks

olivine properties in PPL

Answer 1

-colourless
-fibrous veins of serpentinite and fractures
-high relief
-no cleavage

Question 2

olive likes high order colours that clash, is straight and not a twin

olivine properties in XPL

Answer 2

-high order interference colours may be washed out
-straight extinction
-no twinning

Question 3

classy pale, knives sometimes in clouds, low relief ,no obvi cleavage

plagioclase feldspar in PPL

Answer 3

-colourless
-occasionally in blades in fine grained igneous rocks
-sometimes cloudy
-low relief
-no obvious cleavage

Question 4

classy people order small, like to match and are inclining in extinction

plagioclase feldspar in XPL

Answer 4

-low order white to dark grey interference
-inclined extinction
-repeated barcode twinning

Question 5

clinopyroxene in PPL

Answer 5

-faint grey with no pleochroism
-high relief

Question 6

clinopyroxene in XPL

Answer 6

-vivid colours blue, orange, yellow and green
-simple twinning
-incline extinction

Question 7

amphibole in PPL

Answer 7

-high relief
-greens through to brown with intense pleochroism between these colours and fainter versions

Question 8

amphibole in XPL

Answer 8

-rare twinning
-medium order inteference colours blues, purples and oranges
-inclined extinction

Question 9

biotite mica in PPL

Answer 9

-brown with intense pleochroism to fainter shades
-moderate relief

Question 10

biotite mica in XPL

Answer 10

-high order
-interference colours washed out
-no twinning
-straight extinction

Question 11

k-feldspar
orthoclase in PPL

Answer 11

-colourless
-low relief
-no cleavage

Question 12

k-feldspar
orthoclase in XPL

Answer 12

-inclined extinction
-simple twinning
-low order interference

Question 13

what is pleochroism

Answer 13

when the colours change in the minerals when the slide rotates in PPL

Question 14

what is the cleavage of a mineral

Answer 14

breaks and planes of weaknesses

Question 15

isotropic minerals are

Answer 15

minerals that turn black in XPL

Question 16

birefrigerence is the

Answer 16

refraction that changes in colour in XPL

Question 17

first order birefrigerence colours

Answer 17

grey to red

Question 18

second order birefrigerence colours

Answer 18

darker pastel colours include blue

Question 19

third order birefrigerence colours

Answer 19

lighter pastel

Question 20

euhedral crystal shape

Answer 20

hexagon shape

Question 21

subhedral crystal shape

Answer 21

3 sided shape with a ridgid shape

Question 22

anhedral crystal shape

Answer 22

mangled shape

Question 23

What trait does Garnet have

Answer 23

It is an isotropic mineral meaning it changes to black under XPL