CS 2

Question 1

1. Most gemstones form in the
   A. core.
   B. mantle.
   C. oceanic crust.
   D. continental crust.

Answer 1

D. continental crust.

Question 2

1. Most of the gems in Tanzania’s Umba River Valley are found in
   A. geodes.
   B. placer deposits.
   C. primary deposits.
   D. hydrothermal gem deposits.

Answer 2

B. placer deposits.

Question 3

1. Myanmar’s famous Mogok ruby deposits were formed by
   A. sedimentary processes.
   B. metamorphic processes.
   C. gas crystallization from molten lava.
   D. mineral-rich solutions close to the earth’s surface.

Answer 3

B. metamorphic processes.

Question 4

1. Which gem forms by metamorphism?
   A. Opal
   B. Red beryl
   C. Turquoise
   D. Tanzanite

Answer 4

D. Tanzanite

Question 5

1. Which gem can crystallize in volcanic rock from gases released by magma?
   A. Zircon
   B. Red beryl
   C. Blue sapphire
   D. Vietnamese ruby

Answer 5

B. Red beryl

Question 6

1. Rocks altered by heat and pressure are
   A. granites.
   B. igneous.
   C. sedimentary.
   D. metamorphic.

Answer 6

D. metamorphic.

Question 7

1. Emeralds are rarely found in placer deposits because they’re
   A. too soft.
   B. too rare.
   C. chemically unstable.
   D. unable to withstand much abrasion.

Answer 7

D. unable to withstand much abrasion.

Question 8

1. From granite, pegmatite gems get exotic elements like
   A. chromium and vanadium.
   B. nickel, copper, and cobalt.
   C. beryllium, boron, and lithium.
   D. iron, magnesium, and titanium.

Answer 8

C. beryllium, boron, and lithium.

Question 9

1. A deposit where gems are found in the rocks where they formed is called
   A. primary.
   B. substitute.
   C. secondary.
   D. concentrated.

Answer 9

A. primary.

Question 10

1. Which is a key locality for hydrothermal gems?
   A. Tibet
   B. Tanzania
   C. Ouro Preto, Brazil
   D. Mogok, Myanmar

Answer 10

C. Ouro Preto, Brazil

Question 11

1. Which type of deposit is usually the most profitable for colored stone mining?
   A. Primary
   B. Hard rock
   C. Secondary
   D. Metamorphic

Answer 11

C. Secondary

Question 12

1. Which is a workable alluvial deposit of gem minerals with economic potential?
   A. Vein
   B. Geode
   C. Placer
   D. Primary

Answer 12

C. Placer

Question 13

1. Which is a deposit where gems eroded from the source rock and remained in place nearby?
   A. Eluvial
   B. Primary
   C. Alluvial
   D. Metamorphic

Answer 13

A. Eluvial

Question 14

1. Heat and pressure transform limestone into
   A. opal.
   B. quartz.
   C. granite.
   D. marble.

Answer 14

D. marble.

Question 15

1. Kunzite is most often found in association with
   A. sapphire in lava.
   B. moonstone in basalt.
   C. tourmaline and beryl in pegmatite.
   D. imperial topaz in hydrothermal veins.

Answer 15

C. tourmaline and beryl in pegmatite.