Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
102 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
In igneous rocks, large crystals indicate..., while small crystals indicate… |
slow cooling, quick cooling
|
13
|
|
|
Light that exits through a gem’s crown in a controlled way due to the correct proportions of its cut.
|
Planned light leakage
|
27
|
|
|
Cutting compromises that save weight can also …
|
cause extinction, windows, or both
|
41
|
|
|
natural blue spinel, synthetic blue spinel
|
gems colored by cobalt
|
55
|
|
|
General term for any molten rock.
|
Magma
|
69
|
|
|
A process that occurs when two of the earth’s plates collide, forcing one under the other.
|
Subduction
|
83
|
|
|
The challenges of ... jadeite contribute to its market prices.
|
mining
|
97
|
|
|
A gemstone’s basic color, determined by its selective absorption of light.
|
Bodycolor
|
111
|
|
|
Smoky corundum that turns blue when treated.
|
Dhun
|
125
|
|
|
A curved and ridged fracture in a gemstone, extending from the surface inward.
|
Conchoidal fracture
|
139
|
|
|
How well a gemstone resists light, heat, and chemicals.
|
Stability
|
153
|
|
|
Blemishes or irregularities confined to a pearl’s surface.
|
Surface characteristics
|
167
|
|
|
The network of tiny fractures that develops when an opal loses moisture.
|
Crazing
|
181
|
|
|
A sorter must begin with a huge quantity of pearls to end up with a ...
|
well-matched group
|
195
|
|
|
Narrow section that forms the boundary between the crown and the pavilion, and functions as the gem’s setting edge.
|
Girdle
|
209
|
|
|
... greatly influences a transparent faceted gem’s interaction with light.
|
Cut
|
223
|
|
|
(2 colors) topaz varieties, including imperial topaz, are the most rare and valuable.
|
Red and pink
|
237
|
|
|
Morganite is almost always ... to produce or improve the pink color.
|
heat-treated
|
251
|
|
|
A turquoise imitation made of a mixture of powdered minerals, dyed and bonded with plastic or epoxy resin.
|
Reconstructed turquoise
|
265
|
|
|
Minute inclusion enclosed within a gem; can occur singly or in groups called clouds.
|
Pinpoint
|
279
|
|
|
(3)... combine to create an opal’s unique beauty.
|
Color, pattern, and clarity
|
293
|
|
|
A cabochon with a curved, undercut bottom, designed to lighten the tone of the gem material.
|
Hollowback
|
307
|
|
|
shape with equal triangular faces that meet in a point
|
pyramid
|
321
|
|
|
Mohs of rhodonite, turquoise, opal, and lapis lazuli
|
5 to 6
|
335
|
|
|
Thick-skinned jadeite boulders.
|
Mountain jade
|
349
|
|
|
... inclusions can dramatically affect beauty, value, and durability.
|
Large
|
363
|
|
|
A mineral crystal trapped within a gem as it grows.
|
Included crystal
|
377
|
|
|
Its wide availability, affordable price, and attractive color make ... one of the most popular colored gemstones.
|
amethyst
|
391
|
|
|
Collectors often give ... descriptive names based on their appearance.
|
agates
|
405
|
|
|
What are 3 grades that Afghans recognize for lapis?
|
nili, asmani, sabzi
|
419
|
|
|
Primary mining (3) azurite and azurmalachite
|
US, Namibia, France
|
433
|
|
|
The organ that lines the mollusk’s shell, encloses its soft body, and contains the cells that form pearl sacs and secrete nacre.
|
Mantle
|
447
|
|
|
Only place where charoite is mined.
|
Russia
|
461
|
|
|
Base gem components of ruby
|
aluminum oxide; low silicon environment (feldspars will form if silicon)
|
475
|
|
|
Host rock Mong Hsu rubies
|
marble
|
489
|
|
|
Two countries that generally don't need heat treatment for rubies
|
Madagascar, Malawi
|
503
|
|
|
color elements - blue sapphire
|
environment free of silicon; trace elements of iron and titanium make blue; more iron more blue
|
517
|
|
|
Describe a Burmese blue sapphire
|
Burmese - slightly violetish blue to blue with mod strong to vivid; med dark tone; more intense and saturated than Kashmir, but lacks luster; inky, "royal; form in igneous rocks or pegmatite that have undergone a combo of contact and regional metamorphism blue"
|
531
|
|
|
Types of synthetic tanzanite
|
none
|
545
|
|
|
An oxygen-poor environment that surrounds a gem during heat treatment, causing it to lose oxygen.
|
Reducing environment
|
559
|
|
|
Where and when was alexandrite discovered?
|
discovered in 1830 in Ural Mountains in Russia; few color change stones are as dramatic
|
573
|
|
|
The highest demand is for …
|
mass-market-quality gem rough
|
587
|
|
|
Where was andalusite discovered?
|
Andalusia, Spain
|
601
|
|
|
Crystal system of topaz, characteristics of crystals (2)
|
orthorhombic crystal system; typically elongated with strong parallel grooves
|
615
|
|
|
Rank three layers of topaz color market.
|
three types - imperial (pink and red); less valuable yellow, orange, and brown gems; colorless or greenish gems that are converted to blue
|
629
|
|
|
what kind of gem is helidor?
|
beryl
|
643
|
|
|
A subcategory of species, based on color, transparency, or phenomenon.
|
Gem variety
|
657
|
|
|
cut issues for red beryl
|
preferred are cut perpendicular to crystal's length to get orange-red hue; those cut parallel to crystal's length are more purplish red
|
671
|
|
|
Pakistan is noted for what qualities in aquamarine
|
light greenish blue to blue; large
|
685
|
|
|
What is potch opal?
|
common opal
|
699
|
|
|
What is water opal?
|
water opal - Background ranges from transparent to translucent; shows faint play of color or none at all
|
713
|
|
|
What kind of feldspar is moonstone?
|
potassium feldspar
|
727
|
|
|
In spite of treatment that’s sometimes extensive, ... is the number one colored stone by value imported into the US.
|
emerald
|
741
|
|
|
Where is labradorite mined primarily?
|
mainly in Labrador, Canada
|
755
|
|
|
Fine ... regularly command top prices, sometimescomparable to padparadschas.
|
pink sapphires
|
769
|
|
|
Type of gem - kunzite
|
spodumene
|
783
|
|
|
color range - voiolane
|
rare, translucent to opaque blue violet stone
|
797
|
|
|
In general, attractive colored stones tend to have highly saturated hues and ... tone.
|
medium to medium-dark
|
811
|
|
|
What are the treatments for tourmaline?
|
HEATING - many blue and green are heat treated AFTER cut and polish (lightens and brightens) Gray paraibas are heat treated UNDETECTABLE unless liquid inclusions IRRADIATION - colors can fade; can turn solid green material into colorful mix of green and red
|
825
|
|
|
what type of tourmaline is paraiba tourmaline?
|
elbaite tourmaline
|
839
|
|
|
gem trade name "rubellite"
|
red and pink tourmaline
|
853
|
|
|
color range of cat's eye tourmaline?
|
pink, red, green, blue, greenish blue
|
867
|
|
|
What are the three aluminum garnets?
|
Aluminum garnets (Pyrope - magnesium; Almandite - iron; Spessartite - magnesium)
|
881
|
|
|
color range pyrope
|
purple to orangy red
|
895
|
|
|
The cloudy bluish white light in a moonstone, caused by scattering of light.
|
Adularescence
|
909
|
|
|
A rainbow effect created when light is broken up into spectral hues by thin layers.
|
Iridescence
|
923
|
|
|
Which color of spessartite is most valued
|
"aurora red" most valued - highly sat slightly reddish hue with med to med dark tone
|
937
|
|
|
what kind of gem is andradite?
|
garnet
|
951
|
|
|
... amber has the highest value.
|
Transparent red
|
965
|
|
|
what kind of gem is demantoid
|
garnet
|
979
|
|
|
color range malaya garnet
|
pinkish orange
|
993
|
|
|
A process in which nutrients dissolve in heated chemicals, then cool to form synthetic crystals.
|
Flux growth
|
1007
|
|
|
what is the cause of the rays in star garnets?
|
filled with rutile silk needles
|
1021
|
|
|
type sof synthetic jadeite
|
none
|
1035
|
|
|
chemistry of calcareous coral
|
principally calcium carbonate (calcium, carbon, oxygen, in the form of calcite) polyps secrete calcium carbonate as small, needle like structures or spicules of calcite
|
1049
|
|
|
7 imitations for ivory
|
celluloid (most common), plastic, plaster of Paris, Bone, deer horn, vegetable ivory, doum nut
|
1063
|
|
|
The most prized labradorite type is ... a phenomenal labradorite with brilliant spectral hues.
|
“spectrolite,”
|
1077
|
|
|
what color is cat's eye apatite?
|
usually green or yellow
|
1091
|
|
|
The world market for lapis is steady, prices are low, and availability is ...
|
good
|
1105
|
|
|
transparency of kyanite
|
transparent to trasnlucent
|
1119
|
|
|
treatments for sphene
|
none
|
1133
|
|
|
describe history of synthesizing emeralds
|
flux (1848 Ebelman; 1938 Chantham markets; currently sold by Chantham Created Gems, Kyocera, Russian; beryllium, aluminum, silicon, chromium, oxygen - add molton flux in metal crucible; marektable yield is 15%) Hydrothermal - Lechleitner 1960; 5mm faceted beryl seeds, marketet as Quintessa, marketed as Regency Created Emeralds; Russia Tairus in 1980s; disolving aluminum, beryl, silicon, and chromium in acidic water in an autoclave with non-reactive metal; yield 18% of marketable material)
|
1147
|
|
|
When did Mikimoto start working in pearls?
|
1890
|
1161
|
|
|
What are the grades for GIA nacre in Pearls?
|
GIA Nacre - Acceptable (nucleus not noticeable); nucleus visible, chalky appearance
|
1175
|
|
|
New discoveries of spessartite in the ... made it much more available.
|
1990s
|
1189
|
|
|
gems synthesized by pulling (6)
|
alexandrite, cat's eye alexandrite, green chrysoberyl, corundums, YAG, GGG
|
1203
|
|
|
Market sector where finequality, expensive gemstones are used in unique, handcrafted jewelry pieces.
|
High-end market
|
1217
|
|
|
Light is a form of energy that travels in ...
|
waves
|
1231
|
|
|
... can be made of a variety of materials, including natural or synthetic versions of other gems.
|
Imitations
|
1245
|
|
|
Almost all ... on the market today are fracture filled.
|
emeralds
|
1259
|
|
|
Almost all ... are heat-treated to enhance their color.
|
rubies
|
1273
|
|
|
Fine-quality, ... sapphires make up a small but extremely valuable segment of the sapphire market.
|
untreated
|
1287
|
|
|
(3) are emerald’s color-causing trace elements.
|
Chromium, vanadium, and iron
|
1301
|
|
|
(2) gems must be precisely oriented to display their optical effects properly.
|
Pleochroic and phenomenal
|
1315
|
|
|
Although …. mines produce little today, the rare and vivid hues of ... still set the standard for fine color.
|
Russian alexandrite
|
1329
|
|
|
... tourmaline’s high prices result from a combination of attractive, highly saturated hues, extremely restricted supply, and strong demand.
|
Paraíba
|
1343
|
|
|
treatments akoya (4)
|
bleached, tinted, dyed, irradiated (darkens nucleus)
|
1357
|
|
|
when were tahitian pearls first marketed?
|
160s
|
1371
|
|
|
when did amethyst become more available?
|
most prized quartz for centuries; once considered equal to the big 3, until Brazilian deposit found in 19th century allowed plentiful availability
|
1385
|
|
|
what is the top selling yellow to orange gem
|
citrine
|
1399
|
|
|
what color quartz is easily identified as synthetic or treated?
|
blue quartz
|
1413
|
|
|
what kind of quartz crystalite is Hawk's eye?
|
microcrystalline quartz |
1427
|
