Rock ID's

Question 1

Granite

Answer 1

Phaneritic, quartz, feldspar, 10% black minerals

Question 2

Diorite

Answer 2

phaneritic, chunky, reflective. plag and hornblende, 50/50 split black and white

Question 3

Gabbro

Answer 3

Phaneritic, Dark, visible grains, chunky, 90% dark minerals

Question 4

Andesite

Answer 4

aphanitic, gray, dull

Question 5

Rhyolite

Answer 5

aphanitic, light pink, dull

Question 6

Basalt

Answer 6

aphanitic, black, dull

Question 7

Rhyolite Porphyry

Answer 7

light pink, dull, a few phenocrysts

Question 8

Andesite Porphyry

Answer 8

gray, dull, a few phenocrysts

Question 9

Basalt Porphyry

Answer 9

black, dull, a few phenocrysts

Question 10

Pumice

Answer 10

holes, floats

Question 11

Scoria

Answer 11

holes, sinks

Question 12

Obsidian

Answer 12

glassy, conchoidal fractures

Question 13

Arkose

Answer 13

detrital, sand sized, quartz and pot. feldspar

Question 14

Siltstone

Answer 14

detrital, microscopic grains, gritty on teeth,

Question 15

Breccia

Answer 15

detrital, gravel sized grains, angular grains, ,

Question 16

Shale

Answer 16

detrital, microscopic grains, fissle, would break

Question 17

Conglomerate

Answer 17

detrital, rounded gravel,

Question 18

Quartz Sandstone

Answer 18

detrital, sand sized grains, quartz composition

Question 19

chalk

Answer 19

fizzes with acid, white

Question 20

Bauxite

Answer 20

round pebbles (gravel sized), too round for conglomerate, no fizz

Question 21

Chert

Answer 21

cuts glass, no fizz, microcrystalline, smooth feel, breaks sharply.

Question 22

Fossiliferous Limestone

Answer 22

fizzes, has gravel sized fossils

Question 23

Micritic Limestone

Answer 23

fizzes, microcrystalline

Question 24

Rock Salt

Answer 24

clear, salty taste,

Question 25

Coal

Answer 25

no fizz, black, blocky, marks paper

Question 26

Dolomite

Answer 26

microcrystalline, delayed fizz

Question 27

Oolitic Limestone

Answer 27

fizzes, has sand sized grains.

Question 28

Schist

Answer 28

visible mica flakes aligned in same direction

Question 29

Quartzite

Answer 29

sand grains without spaces, cuts glass no fizz

Question 30

Anthracite

Answer 30

black, marks paper (weaker than coal)

Question 31

Gneiss

Answer 31

black and white bands running in same direction

Question 32

Marble

Answer 32

reflective cleavage planes, reacts to acid

Question 33

Slate

Answer 33

thin, flat, smooth, harder than Shale

Question 34

Phyllite

Answer 34

shiny not flat like Slate, wavy