Colored Stones Final Assessment: 209
Questions with Verified Answers 2026 Update
1. All garnets have essentially the same - ANSWER crystal structure
2. Tsavorite and hessonite are both varieties of - ANSWER Grossular
3. The most desirable, vibrant, and rare blue natural spinels are colored by -
ANSWER cobalt and iron
4. Horsetail inclusions are found in - ANSWER demantoid
5. Mandarin garnet has been used as a trade name for - ANSWER spessartine
6. Tsavorite is colored by - ANSWER Vanadium
7. The substitution of one chemical element for another in the crystal structure
of a mineral is called - ANSWER isomorphous replacement
8. A treatment that makes turquoise less porous without the use of polymers
and improves its ability to take a good polish is - ANSWER the Zachery
method
9. Which of the following does turquoise usually form in? - ANSWER
limonite
10.The world's largest producer of turquoise today is - ANSWER the
southwestern United States
11.The only source of charoite is - ANSWER Russia
12.Stabilized turquoise is a trade term for - ANSWER polymer-impregnated
turquoise
13.Light-colored or colorless spodumene can be treated to a kunzite color by -
ANSWER irradiation followed by careful heating
14.Spectrolite is a variety of - ANSWER Labradorite
1
,15.By which era had moonstone gone out of style? - ANSWER Art Deco
16.Rainbow moonstone is a trade term for a type of - ANSWER Labradoritetree
resin hardened over time up to 1000 years - ANSWER amber
17.inmature amber - ANSWER copal
18.most valuable amber - ANSWER transparent red
19.cause amber color change over time - ANSWER oxidation
20.circular marks sometimes left in amber when heat and oil it - ANSWER sun
spangles
21.coral most valuable color - ANSWER intense red
22.color of conchiolin coral - ANSWER black and gold
23.most valuable ivory - ANSWER elephant tusks
24.ornamental form of lignite coal - ANSWER jet
25.major jet source - ANSWER England
26.A natural, inorganic substance with a characteristic chemical composition
and usually characteristic crystal structure is a(n) - ANSWER mineral
27.Which of the following is a gem variety - ANSWER demantoid
28.A substance that consists of atoms of only one kind is a - ANSWER
Chemicals element
29.A broad gem category based on chemical composition and crystal structure
is a - ANSWER gem species.
30.Kunzite is most often found in association with - ANSWER tourmaline and
beryl in pegmatite.
31.Velvety blue to violetish blue, in medium to medium-dark tones, with strong
to vivid saturation - ANSWER Fine sapphire
2
,32.What trace elements cause the blue of sapphire? - ANSWER Iron and
titanium
33.A smokey corundum that turns blue when treated - ANSWER Dhun
34.Higher levels of iron make basalt-hosted sapphires ______ than non-basaltic
saphhires. - ANSWER Darker
35.What is the trade name cosidered as the finest blue sapphire? - ANSWER
Kashmir
36.A common sapphire characteristic - ANSWER Color zoning
37.Most sapphires are ______ to improve their appearance. - ANSWER Heat
treated
38.Fine quality, untreated sapphires make up ______ of the sapphire market. -
ANSWER A small but extremely valuable segment
39.What country buys about half of the blue sapphires on the world market? -
ANSWER USA
40.Kashmir sapphires owe their reputation to a brief period of output during
what time period? - ANSWER 1880s
41.What country is a major center of the corrundum trade, funneling a steady
flow of gems from worldwide sources into the consumer market? -
ANSWER Thailand
42.What country is the world's largest source of dark blue, commercial quality
blue sapphires? - ANSWER Australia
43.What country has become a significant source of good to fine qualtiy blue
sapphires? - ANSWER Madagascar
44.The most common sapphire synthesis method - ANSWER Flame fusion
45.Milky, greyish, or brownish corundum that can be treated to a fine blue color
- ANSWER Geuda
3
, 46.Color of fine blue sapphire - ANSWER Blue to violetish blue
47.Blue sapphires that orginate in basaltic rock generally have a... - ANSWER
Higher iron content
48.Finer quality Kashmir blue sapphires typically show what type of
appearance? - ANSWER Velvety
49."Inky" sapphires generally originate from... - ANSWER Australia
50.Most fine sapphires over 100 cts. come from what country? - ANSWER Sri
Lanka
51.What country emerged in the 1990s as a significant source of fine to good
quality saphhire? - ANSWER Madagascar
52.What country is the world's largest blue saphhire exporter? - ANSWER
Thailand
53.The sapphire market level supplied by Switzerland is - ANSWER Upper
54.When did Madagascar become a significant source of blue sapphire? -
ANSWER 1990s
55.What location supplies sapphires that are most likely not heat-treated? -
ANSWER Yogo Gulch
56.A Kashmir sapphire's blue is also known as - ANSWER Cornflower blue
57.A Burmese sapphire's blue is known as ______ blue and is considered
somewhat _______. - ANSWER Royal; inky
58.The "Ceylon" or "Sri Lanka" sapphire's saturation is ______ and ______.
The tone is ______ to ______. - ANSWER Greyish and strong saturation
Light to medium light tone
59.The "Palin" or "Cambodian" sapphires are typically ______ to ______ in
color and look best when fashioned into smaller sizes. - ANSWER Violetish
blue to slightly greenish blue
4
Questions with Verified Answers 2026 Update
1. All garnets have essentially the same - ANSWER crystal structure
2. Tsavorite and hessonite are both varieties of - ANSWER Grossular
3. The most desirable, vibrant, and rare blue natural spinels are colored by -
ANSWER cobalt and iron
4. Horsetail inclusions are found in - ANSWER demantoid
5. Mandarin garnet has been used as a trade name for - ANSWER spessartine
6. Tsavorite is colored by - ANSWER Vanadium
7. The substitution of one chemical element for another in the crystal structure
of a mineral is called - ANSWER isomorphous replacement
8. A treatment that makes turquoise less porous without the use of polymers
and improves its ability to take a good polish is - ANSWER the Zachery
method
9. Which of the following does turquoise usually form in? - ANSWER
limonite
10.The world's largest producer of turquoise today is - ANSWER the
southwestern United States
11.The only source of charoite is - ANSWER Russia
12.Stabilized turquoise is a trade term for - ANSWER polymer-impregnated
turquoise
13.Light-colored or colorless spodumene can be treated to a kunzite color by -
ANSWER irradiation followed by careful heating
14.Spectrolite is a variety of - ANSWER Labradorite
1
,15.By which era had moonstone gone out of style? - ANSWER Art Deco
16.Rainbow moonstone is a trade term for a type of - ANSWER Labradoritetree
resin hardened over time up to 1000 years - ANSWER amber
17.inmature amber - ANSWER copal
18.most valuable amber - ANSWER transparent red
19.cause amber color change over time - ANSWER oxidation
20.circular marks sometimes left in amber when heat and oil it - ANSWER sun
spangles
21.coral most valuable color - ANSWER intense red
22.color of conchiolin coral - ANSWER black and gold
23.most valuable ivory - ANSWER elephant tusks
24.ornamental form of lignite coal - ANSWER jet
25.major jet source - ANSWER England
26.A natural, inorganic substance with a characteristic chemical composition
and usually characteristic crystal structure is a(n) - ANSWER mineral
27.Which of the following is a gem variety - ANSWER demantoid
28.A substance that consists of atoms of only one kind is a - ANSWER
Chemicals element
29.A broad gem category based on chemical composition and crystal structure
is a - ANSWER gem species.
30.Kunzite is most often found in association with - ANSWER tourmaline and
beryl in pegmatite.
31.Velvety blue to violetish blue, in medium to medium-dark tones, with strong
to vivid saturation - ANSWER Fine sapphire
2
,32.What trace elements cause the blue of sapphire? - ANSWER Iron and
titanium
33.A smokey corundum that turns blue when treated - ANSWER Dhun
34.Higher levels of iron make basalt-hosted sapphires ______ than non-basaltic
saphhires. - ANSWER Darker
35.What is the trade name cosidered as the finest blue sapphire? - ANSWER
Kashmir
36.A common sapphire characteristic - ANSWER Color zoning
37.Most sapphires are ______ to improve their appearance. - ANSWER Heat
treated
38.Fine quality, untreated sapphires make up ______ of the sapphire market. -
ANSWER A small but extremely valuable segment
39.What country buys about half of the blue sapphires on the world market? -
ANSWER USA
40.Kashmir sapphires owe their reputation to a brief period of output during
what time period? - ANSWER 1880s
41.What country is a major center of the corrundum trade, funneling a steady
flow of gems from worldwide sources into the consumer market? -
ANSWER Thailand
42.What country is the world's largest source of dark blue, commercial quality
blue sapphires? - ANSWER Australia
43.What country has become a significant source of good to fine qualtiy blue
sapphires? - ANSWER Madagascar
44.The most common sapphire synthesis method - ANSWER Flame fusion
45.Milky, greyish, or brownish corundum that can be treated to a fine blue color
- ANSWER Geuda
3
, 46.Color of fine blue sapphire - ANSWER Blue to violetish blue
47.Blue sapphires that orginate in basaltic rock generally have a... - ANSWER
Higher iron content
48.Finer quality Kashmir blue sapphires typically show what type of
appearance? - ANSWER Velvety
49."Inky" sapphires generally originate from... - ANSWER Australia
50.Most fine sapphires over 100 cts. come from what country? - ANSWER Sri
Lanka
51.What country emerged in the 1990s as a significant source of fine to good
quality saphhire? - ANSWER Madagascar
52.What country is the world's largest blue saphhire exporter? - ANSWER
Thailand
53.The sapphire market level supplied by Switzerland is - ANSWER Upper
54.When did Madagascar become a significant source of blue sapphire? -
ANSWER 1990s
55.What location supplies sapphires that are most likely not heat-treated? -
ANSWER Yogo Gulch
56.A Kashmir sapphire's blue is also known as - ANSWER Cornflower blue
57.A Burmese sapphire's blue is known as ______ blue and is considered
somewhat _______. - ANSWER Royal; inky
58.The "Ceylon" or "Sri Lanka" sapphire's saturation is ______ and ______.
The tone is ______ to ______. - ANSWER Greyish and strong saturation
Light to medium light tone
59.The "Palin" or "Cambodian" sapphires are typically ______ to ______ in
color and look best when fashioned into smaller sizes. - ANSWER Violetish
blue to slightly greenish blue
4
