CS 23

Question 1

1. The color of blue zircon is usually
   A. natural.
   B. due to irradiation.
   C. due to heat treatment.
   D. due to irradiation followed by heating.

Answer 1

due to heat treatment.

Question 2

1. The cause of color in peridot is
   A. iron.
   B. nickel.
   C. vanadium.
   D. chromium.

Answer 2

iron

Question 3

1. Which characteristic easily distinguishes colorless zircon from diamond and synthetic cubic zirconia?
   A. Fire
   B. Heft
   C. Brilliance
   D. Strong doubling

Answer 3

Strong doubling

Question 4

1. Paraíba tourmaline is colored by
   A. iron.
   B. cobalt.
   C. copper.
   D. chromium.

Answer 4

copper

Question 5

1. Which countries produce the finest peridot?
   A. Myanmar and Pakistan
   B. Madagascar and Sri Lanka
   C. Afghanistan and Cambodia
   D. The United States and Brazil

Answer 5

Myanmar and Pakistan

Question 6

1. What is peridot’s rating on the Mohs scale?
   A. 2 to 3
   B. 5 to 5.5
   C. 6.5 to 7
   D. 9

Answer 6

6.5 to 7

Question 6

1. For the most part, rubellite tourmaline is colored by
   A. iron.
   B. copper.
   C. chromium.
   D. manganese.

Answer 6

manganese

Question 7

1. Most gem tourmalines form in
   A. marble.
   B. limestone.
   C. pegmatites.
   D. metamorphic rock.

Answer 7

pegmatites

Question 8

1. Metamict zircons are described as
   A. low zircons.
   B. high zircons.
   C. normal zircons.
   D. diffusion-treated zircons.

Answer 8

low zircons

Question 9

1.Most fine chrome tourmaline comes from Kenya and
A. Brazil.
B. Tanzania.
C. Sri Lanka.
D. Madagascar.

Answer 9

Tanzania

Question 10

1. The most expensive variety of tourmaline is
   A. Paraíba.
   B. chrome.
   C. rubellite.
   D. indicolite.

Answer 10

Paraiba

Question 11

1. Which of the following trade terms is used for blue tourmaline?
   A. Chrome
   B. Rubellite
   C. Verdelite
   D. Indicolite

Answer 11

Indicolite

Question 12

1. The world’s largest producer of gem-quality tourmaline is
   A. Brazil.
   B. Zambia.
   C. Tanzania.
   D. Madagascar.

Answer 12

Brazil

Question 13

1. Most gem tourmalines are
   A. uvite.
   B. schorl.
   C. elbaite.
   D. dravite.

Answer 13

elbaite

Question 14

1. Many green and blue tourmalines are lightened by
   A. heating.
   B. bleaching.
   C. irradiation.
   D. irradiation followed by heating.

Answer 14

heating