CBJ Gemstone and Setting Techniques

Question 1

What is the Mohs hardness rating of diamond?

Accepted Answer

10

Answer

7

Answer

8

Answer

9

Question 2

What Mohs hardness do sapphire and ruby share?

Accepted Answer

9

Answer

7

Answer

8

Answer

10

Question 3

What distinguishes a ruby from a blue sapphire at the chemical level?

Accepted Answer

Chromium content causing red color vs. iron and titanium causing blue

Answer

Different crystal structure

Answer

Country of origin

Answer

Different hardness rating

Question 4

What is the approximate Mohs hardness range of opal?

Accepted Answer

5.5–6.5

Answer

7–7.5

Answer

8–8.5

Answer

9–9.5

Question 5

Which gemstone is famous for displaying asterism (a star effect)?

Accepted Answer

Star sapphire

Answer

Emerald

Answer

Tanzanite

Answer

Aquamarine

Question 6

What is the most common treatment applied to commercial sapphires to improve color and clarity?

Accepted Answer

Heat treatment

Answer

Fracture filling with glass

Answer

Surface diffusion

Answer

Irradiation