12 need to know igneous rocks

Question 1

granite is usually what colour

Answer 1

light coloured

Question 2

granite is usually what grained

Answer 2

medium to coarse

Question 3

granite is usually made of

Answer 3

quartz, orthoclase, muscovite, biotite, hornblende

Question 4

granodiorite has more ………. than granite

Answer 4

plagioclase feldspar

Question 5

granodiorite is usually darker than granite because

Answer 5

it has abundant biotite mica and hornblende

Question 6

biotite mica is …………..than muscovite mica

Answer 6

darker

Question 7

in granodiorite the lighter minerals are

Answer 7

quartz and feldspar

Question 8

in granodiorite the darker minerals are

Answer 8

hornblende or biotite mica

Question 9

rhyolite is basically a

Answer 9

fine grained granite

Question 10

rhyolite often contains ………. showing rapid cooling

Answer 10

glassy bits and voids

Question 11

rhyolite is very often …….. with the minerals aligning themselves

Answer 11

flow banded

Question 12

pumice has loads of ………. which make it float

Answer 12

vesicles

Question 13

pumice has the same composition as

Answer 13

rhyolite

Question 14

obsidian is formed in about

Answer 14

a few hours

Question 15

pegmatite is classified as a

Answer 15

intrusive igneous rock

Question 16

pegmatite has what type of grain

Answer 16

coarse grained

Question 17

pegmatite is any rock that has unusually

Answer 17

large crystals

Question 18

crystals of pegmatite are usually a few

Answer 18

cms or metres

Question 19

diorite is simular to

Answer 19

granite

Question 20

diorite has a……….. colour

Answer 20

salt and pepper

Question 21

diorite is distinguished from granite by having ….. …

Answer 21

no visible quartz

Question 22

andersite is usually what colour

Answer 22

grey to black

Question 23

andersites have crystals mainly made of

Answer 23

plagioclase feldspar, and pyroxene

Question 24

quick opportunities meet brown hares. is for remembering what

Answer 24

the minerals in granite

Question 25

gabbro has what grain

Answer 25

course grained

Question 26

gabbro is heavier than

Answer 26

granitic rocks

Question 27

gabbro is usually ………. coloured

Answer 27

dark

Question 28

gabbros normally has no …….

Answer 28

quartz

Question 29

is dolrite intrusive or extrusive ?

Answer 29

intrusive