Petrology

Question 1

Sphalerite

Answer 1

ZnS or (Zn,Fe)S
primary ore of zinc (also contains iron, cadmium, manganese)
AKA zinc blend

Question 2

Galena

Answer 2

PbS ore of lead

Question 3

Igneous texture in which crystals are visible

Answer 3

Phaneritic

Question 4

Fine-grained or glassy texture of igneous rocks

Answer 4

Aphanitic

Question 5

Plutonic rock consisting entirely of ferromagnesians (olivine and pyroxene) and dark, calcic plagioclase feldspar. If ultramafic, the feldspar is virtually absent.

Answer 5

Gabbro

Question 6

An intermediate plutonic rock with salt and pepper coloring.

Answer 6

Diorite

Question 7

The volcanic equivalent of gabbro

Answer 7

Basalt

Question 8

Volcanic equivalent of granite

Answer 8

Rhyolite

Question 9

Pluton in which contacts are roughly parallel to any structure in the country rock

Answer 9

Concordant

Question 10

Pluton in which contacts cut across structure of country rock

Answer 10

Discordant

Question 11

Cylindrical pitons, elongated in one dimension (usually vertical), believed to be conduits that carried magma to a volcano above them

Answer 11

Pipes or necks

Question 12

Tabular discordant plutons

Answer 12

Dikes

Question 13

Tabular concordant plutons

Answer 13

Sills

Question 14

A sedimentary rock made up of many smaller rocks.

Answer 14

Conglomerate.

Question 15

Single tetrahedron magnesium iron silicate

Answer 15

Olivine

Question 16

Single chain calcium magnesium iron aluminum silicate

Answer 16

Pyroxene

Question 17

Augite

Answer 17

A pyroxene

Question 18

Hornblende

Answer 18

An amphibole

Question 19

Double chain, similar to pyroxene

Answer 19

Amphibole

Question 20

Olivine

Answer 20

Magnesium iron silicate, single tetrahedron

Question 21

Lithification

Answer 21

Process of converting sediments to a truly cohesive solid

Question 22

Diagenesis

Answer 22

Whole set of processes of lithification

Question 23

Limestone

Answer 23

Rock made of calcium and magnesium carbonate, or more specifically, calcite (calcium carbonate)

Question 24

Dolostone (aka dolomite)

Answer 24

Rock made of dolomite, a calcium-magnesium carbonate mineral

Question 25

Stalactites and stalagmites are examples of _____.

Answer 25

Dripstone

Question 26

Emerald

Answer 26

A beryl with trace Chromium, sometimes Vanadium.

Question 27

Beryl

Answer 27

Beryllium aluminum silicate
Includes aquamarine (blue-green), emerald (deep green), and morganite (pink)

Question 28

Corundum

Answer 28

Aluminum oxide; rubies and sapphire

Question 29

Ruby

Answer 29

Corundum - color comes from trace of chromium

Question 30

Sapphire

Answer 30

A corundum - all gem quality corundum besides ruby. Color from tiny needles of rutile. Blue, pink, green, violet, gray, or yellow.

Question 31

Rutile

Answer 31

Titanium dioxide; red, brown or black. Responsible for color in some minerals such as rose quartz and sapphire

Question 32

Orthoclase

Answer 32

K-spar, iron oxide gives red or pink color, can also be white

Question 33

Albite

Answer 33

Plagioclase, sodium end-member, sodium aluminum silicate, striations?

Question 34

Opal

Answer 34

A hydrous silicon dioxide, amorphous, non-crystalline, non-definite composition, a mineraloid

Question 35

Tuff

Answer 35

Sandstone made from volcanic particles

Question 36

Arkose

Answer 36

Sandstone with 25%+ feldspar

Question 37

Wacke

Answer 37

Sandstone with 10%+ matrix (poorly sorted) (“dirty”)

Question 38

Arenite

Answer 38

Well sorted sandstone, little matrix and little cement

Question 39

What does the presence of feldspar and lithic grains in sandstone indicate?

Answer 39

Formed close to mountains