1. Ruby refers to a kind of red gem.

A. the carbonate gemstone of ruby

B. ruby

C. red corundum gem

D. red silicate gemstone

Correct answer: red corundum gem

2. What metal ions color rubies?

A. Iron ions

B. titanium ions

C. manganese ions

D. chromium ion

Correct answer: chromium ion

3. The mineralogical name of emerald is:

A. emerald

B. emerald

C. andalusite

D. sapphire

Correct answer: beryl

4. Opal in gemology has cat's eye effect.

A. golden green jade

B.topaz

C. sapphire

Silver jadeite

Correct answer: Emerald

5. What crystal system does garnet belong to?

A. ternary crystal system

B. tetragonal system

C. hexagonal system

D. equiaxed crystal system

Correct answer: equiaxed crystal system

1. The common crystal forms of diamonds are:

A. cube

B. octahedron

C. rhombic dodecahedron

D. square column

Correct answer: cube # octahedron # rhombic dodecahedron

2. Diamonds have the highest refractive index and hardness among transparent gems in nature.

A. correct

B. mistakes

Correct answer: a

3. The 4C grade evaluation of diamonds includes:

A. color

B. Notes

C. clear

D. cutting

Correct answer: color # clarity # cut.

4, diamond formed in which part of the earth:

A. The Earth's core

B. covering

C. shell

D. surface

Correct answer: mantle

5. What kind of rocks do primary diamonds grow in?

A. Granite

B. sandstone

C. kimberlite

D. marble

Correct answer: Kimberlite