CS 4

Question 1

Which phenomenon is a broad color flash?

Answer 1

Labradorescence

Question 2

Which transition element causes a greater variety of gem colors than any other?

Answer 2

Iron

Question 3

Which element does chromium substitute for to cause ruby’s red?

Answer 3

Aluminun

Question 4

Which element causes the color of both almandine and peridot?

Answer 4

Iron

Question 5

Which element causes the finest reds and greens in gemstones?

Answer 5

Chromium

Question 6

The pattern of dark vertical lines or bands shown by certain gems when viewed through a spectroscope is called

Answer 6

Absorption Spectrum

Question 7

When a gem’s crystal structure splits light into two rays that each travel at a slightly different speed and direction, it’s called

Answer 7

Double Refraction

Question 8

What is the only type of gem that can show pleochroism?

Answer 8

Double Refractive

Question 9

Adularescence is caused by

Answer 9

Scattering of light

Question 10

Which gem can show three pleochroic colors?

Answer 10

Iolite

Question 11

The best-known and most valuable chatoyant gem is cat’s-eye

Answer 11

Chrysoberyl

Question 12

The process where electrons that selectively absorb light are passed back and forth between neighboring impurity ions is known as

Answer 12

Charge Transfer

Question 13

A gem colored by an element that is part of its basic chemistry is called

Answer 13

idiochromatic

Question 14

Which components of a transition element’s atoms can produce color in gems?

Answer 14

Electrons

Question 15

In many blue sapphires, the intervalence charge transfer that causes the color is between

Answer 15

Iron and Titanium