CS 6

Question 1

1. Written information on dyeing gems dates back to about

Answer 1

200 BC

Question 2

1. Quartz or topaz with a thin layer of gold deposited on the surface is known as

Answer 2

Aqua aura

Question 3

Treaters use sugar treatment to enhance

Answer 3

Opal

Question 4

1. Heat can lighten amethyst’s purple by

Answer 4

causing changes in color centers

Question 5

1. Heat treatment in a reducing environment can

Answer 5

deepen blue color in sapphire.

Question 6

1. How deep is the color layer that lattice diffusion with titanium or chromium creates in corundum?

Answer 6

A. 0.01 to 0.50 mm

Question 7

1. Creating asterism with heat treatment is most common in

Answer 7

synthetic corundum

Question 8

1. After irradiation, which gem’s color is stable under normal wearing conditions?

Answer 8

Golden beryl

Question 9

1. Which gem is commonly heat treated?

Answer 9

Amber

Question 10

1. What coloring agents do treaters use during lattice diffusion to create a shallow layer of blue color in corundum?

Answer 10

Titanium and iron

Question 11

1. Jadeite is often

Answer 11

bleached and polymer impregnated

Question 12

1. What agent can create a shallow layer of asterism when it’s introduced below the surface of a corundum cabochon by lattice diffusion?

Answer 12

Titanium oxide

Question 13

1. For effective clarity enhancement, the material used to fill a gem’s fractures must have nearly the same

Answer 13

refractive index as the gem.

Question 14

1. When a filler is so extensive that it becomes a significant component of the finished product, the result is described as

Answer 14

a composite.

Question 15

1. Which of these is considered a gem treatment?

Answer 15

Dyeing