CS 13

Question 1

1. Milky, grayish, or brownish corundum that can be treated to a fine blue color is called
   A. dhun.
   B. geuda.
   C. cornflower.
   D. parti-colored.

Answer 1

geuda

Question 2

1. Which of the following countries is the biggest market for sapphire?
   A. Korea
   B. The United States
   C. Canada
   D. Australia

Answer 2

The United States

Question 3

1. Blue sapphire’s pleochroic colors are typicallyA. green and blue.
   B. purple and blue.
   C. green-blue and violet.
   D. slightly greenish blue and slightly violetish blue.

Answer 3

slightly greenish blue and slightly violetish blue.
Pleochroism in blue sapphire typically appears as a variation between slightly greenish blue and slightly violetish blue in different crystal directions.

Question 4

1. When trade members use the single word “sapphire,” they are referring to
   A. any blue stone.
   B. corundum in any color.
   C. the blue variety of corundum.
   D. both synthetic and natural blue corundum.

Answer 4

blue variety of corundrum

Question 5

1. What trace elements cause blue sapphire’s color?
   A. Titanium and iron
   B. Chromium and iron
   C. Manganese and iron
   D. Magnesium and iron

Answer 5

Titanium and Iron

Question 6

1. Which of the following sources emerged in the 1990s as a significant source of good- to fine-quality sapphire?
   A. Kashmir
   B. Australia
   C. Sri Lanka
   D. Madagascar

Answer 6

Madagascar

Question 7

1. Blue sapphires that originate in basaltic rock generally have
   A. low iron content.
   B. high iron content.
   C. high chromium content.
   D. high manganese content.

Answer 7

high iron content

Question 8

1. Minute inclusions can give Kashmir sapphires a(n)
   A. light tone.
   B. inky color.
   C. very dark tone.
   D. velvety appearance.

Answer 8

Velvety appearance

Question 9

1. Regions associated with basalt-related sapphire include Cambodia, Thailand, Nigeria, and
   A. Kashmir.
   B. Australia.
   C. Myanmar.
   D. Sri Lanka.

Answer 9

Australia

Question 10

1. Australian sapphire’s blue color is often described as
   A. inky.
   B. royal.
   C. velvety.
   D. cornflower.

Answer 10

Inky

Question 11

1. Blue sapphire’s most common crystal habit is a(n)
   A. octahedron.
   B. twinned octahedron.
   C. long hexagonal prism.
   D. spindle-shaped hexagonal pyramid or bipyramid.

Answer 11

spindle-shaped hexagonal pyramid or bipyramid.

Question 12

1. The most highly valued blue sapphire hues are
   A. blue to green-blue.
   B. blue to violet-blue.
   C. blue to greenish blue.
   D. blue to violetish blue.

Answer 12

blue to violetish blue.

Question 13

1. Most fine sapphires over 100 cts. come from
   A. Montana.
   B. Australia.
   C. Sri Lanka.
   D. Cambodia.

Answer 13

Sri Lanka

Question 14

1. Kashmir’s most important sapphire production period was from
   A. 1789 to 1802.
   B. 1840 to 1851.
   C. 1881 to 1887.
   D. 1901 to 1936.

Answer 14

1881 to 1887.

Question 15

1. What location supplies sapphires that are probably not heat treated?
   A. Myanmar
   B. Rubyvale
   C. Rock Creek
   D. Yogo Gulch

Answer 15

Yogo Gulch