1
Q
- Written information on dyeing gems dates back to about
A
200 BC
2
Q
- Quartz or topaz with a thin layer of gold deposited on the surface is known as
A
Aqua aura
3
Q
Treaters use sugar treatment to enhance
A
Opal
4
Q
- Heat can lighten amethyst’s purple by
A
causing changes in color centers
5
Q
- Heat treatment in a reducing environment can
A
deepen blue color in sapphire.
6
Q
- How deep is the color layer that lattice diffusion with titanium or chromium creates in corundum?
A
A. 0.01 to 0.50 mm
7
Q
- Creating asterism with heat treatment is most common in
A
synthetic corundum
8
Q
- After irradiation, which gem’s color is stable under normal wearing conditions?
A
Golden beryl
9
Q
- Which gem is commonly heat treated?
A
Amber
10
Q
- What coloring agents do treaters use during lattice diffusion to create a shallow layer of blue color in corundum?
A
Titanium and iron
11
Q
- Jadeite is often
A
bleached and polymer impregnated
12
Q
- What agent can create a shallow layer of asterism when it’s introduced below the surface of a corundum cabochon by lattice diffusion?
A
Titanium oxide
13
Q
- For effective clarity enhancement, the material used to fill a gem’s fractures must have nearly the same
A
refractive index as the gem.
14
Q
- When a filler is so extensive that it becomes a significant component of the finished product, the result is described as
A
a composite.
15
Q
- Which of these is considered a gem treatment?
A
Dyeing
