GIA Colored Stones Exam 201-250 Flashcards Preview

Colored Stones Exam > GIA Colored Stones Exam 201-250 > Flashcards

Flashcards in GIA Colored Stones Exam 201-250 Deck (50)
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1
Q

An opal with a dark background that is tranparent to semi_transparent and is valued for its strong play_of_color is known as _______ .

A

Black crystal opal

2
Q

What gemstone carries thousands of years of cultural significance; especially in Asia?

A

Jade

3
Q

Which is more valuable jadeite or nephrite?

A

Jadeite

4
Q

What are jadeites three most important qualities?

A

color; transparency; texture

5
Q

In addition to green what eight other colors can jadeite be?

A

lavender; red; orange; yellow; black; white; brown; gray

6
Q

What is the trade term for the most valuable jadeite?

A

Imperial

7
Q

What transparency is the most highly valued jadeite?

A

Semitransparent

8
Q

Intense green.

A

Finest Jadeite

9
Q

What country is the main polishing center for jadeite?

A

China

10
Q

True or False: The intense global demand for jadeite exceeds production?

A

TRUE

11
Q

Why are jadeite and nephrite both called jade?

A

The chemical differences are so subtle.

12
Q

A readily available; lower_priced alternative to jadeite is ______ .

A

Nephrite

13
Q

Gemstone jewelry that is carved from a single piece of rough is called a ________ .

A

holoith

14
Q

In jade what is “mottling”?

A

An uneven distribution of color against a contrasting background

15
Q

What is mountain jade?

A

Thick_skinned jadeite boulders

16
Q

The coarsest texture category of jadeite is known as the term __________ .

A

new mine

17
Q

The finest texture category of jadeite is known as the term _______ .

A

old mine

18
Q

The term “relatively old mine” refers to what rexture category of jadeite?

A

medium

19
Q

Weathered thin_skinned jadeite boulders are known as __________ .

A

river jade

20
Q

Spots of color near the surface of a jadeite boulder; where the skin is thin enough to allow color to show through.

A

show points

21
Q

What is type A jadeite?

A

natural jadeite enhanced only with a surface coating of wax.

22
Q

Natural jadeite that’s bleached in acid to remove undesirable staining; then impregnated with wax or polymers is called __________ .

A

type C jadeite

23
Q

In what area was jadeite first fashioned and used as an ornamental object?

A

Central America

24
Q

The finest quality jadeite is called __________ .

A

Imperial jadeite

25
Q

Jadeite’s finest green color is caused by _______ .

A

Chromium

26
Q

The most valuable level of transparency in jadeite is __________ .

A

semitranpsrent

27
Q

The toughness of jadeite is _________ .

A

exceptional

28
Q

The finest texture category of jadeite is known as _______ .

A

old mine

29
Q

What type is bleached and impregnated jadeite?

A

Type B

30
Q

What type is dyed jadeite?

A

Type C

31
Q

In Myanmar; the center of the jadeite mining district is ____________ .

A

Hpakan

32
Q

Spots of color near the surface of a jadeite boulder; where the skin is thin enough to see through; are called ____________ .

A

show points

33
Q

What country recently emerged as a valuable source of black jadite?

A

Guatemala

34
Q

Polar jade is fine quality __________.

A

nephrite

35
Q

What color is caused by the heat treatment of jadeite?

A

orange

36
Q

Spinach jade is used to describe a color of ____________ .

A

nephrite

37
Q

What country is a major source of nephrite?

A

New Zeland

38
Q

What gemstone commands the highest per_carat price of all colored stones?

A

ruby

39
Q

Where does ruby rate on the Mohs hardness scale?

A

9

40
Q

Red to slightly purplish red; med to med-dark tone; vivid saturation

A

Finest ruby

41
Q

What trace element causes ruby to be red?

A

Chromium

42
Q

What causes fluorescence in a ruby?

A

Chromium

43
Q

In what type of deposits are the finest rubies found?

A

marble deposits

44
Q

Basalt_hosted rubies have higher levels of what element?

A

iron

45
Q

The iron in basalt_hosted rubies inhibit what?

A

fuorescence

46
Q

What is used to treat almost all rubies?

A

heat

47
Q

What country IMPORTS the most rubies than any other?

A

USA

48
Q

What country is the world’s largest marketing center?

A

Thailand

49
Q

What country EXPORTS the most of the faceted commercial_ quality rubies?

A

Thailand

50
Q

Switzerland deals with what type of rubies from other countries?

A

high_end