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DANBURITE: Click on
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DATOLITE: Click on
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DIAMOND: Click on the
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DICHORIC: This term refers to a gem that appears to have two different
colors or shades when viewed from different directions.
DIFFRACTION: This occurs when white lights splits into its constituent
spectral colors, the colors of the rainbow, when it passes through a hole
or grating.
DISPERSION: This occurs when white lights splits into its constituent
spectral colors, the colors of the rainbow, when it passes through an
inclined surface, such as those on a prism or a faceted gemstone. Dispersion
in gems is called fire.
DOLOMITE: Click on
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DOUBLE: Similar to rolled gold but instead of base metal the surface
precious metal 'veneer' is bonded to another precious metal, usually silver
or another carat gold of a different color. Also known as "Onlay". Please
refer to the
Precious Metals Buyer's Guide for
more information.
DOUBLE REFRACTION: This phenomenon occurs when each ray of light
is split in two as it enters a non-cubic mineral.
DOUBLET: This is composite stone made of two pieces cemented or
glued together.
DROP EARRING: An earring that hangs below the earlobe. Also known
as a "Dangle" earring.
DUMORTIERITE: Click
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EGLOMAIZE: Reverse painting on glass.
EKANITE: Click on the
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EMERALD: Click on the
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ENAMEL: Powdered colored glass fused onto the surface of the piece
of jewelry. The following types of enamel-work are illustrated and defined
in this book: champleve, cloisonné, guilloche, Jaipur, plique-a-jour,
and polychrome.
ENSTATITE: Click on
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EPIDOTE: Click on the
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ETRUSCAN: A 19th-century Antique Revival style of jewelry resembling
that was produced in Tuscany, central Italy, during the 7th to 6th centuries
B.C. by the ancient Etruscans. The work is characterized by minute beads
of gold soldered onto a gold background and forming a pattern. See GRANULATION.
ETUI: A case hanging from a chatelaine that contains useful implements
such as scissors, pencil, small spoon, pad, ear cup cleaner, toothpick,
etc.
EUCLASE: Click on the
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EUDIALYTE: Click on
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EUROPEAN CUT: Method of cutting that varies from the American brilliant
approach in that proportions are worked out according to light falling
directly from above on the crown.
FABERGE, PETER CARL (1846-1920): Jeweler to the
Russian czar, famous for the gemstone Easter eggs made for the czar's
mother and wife.
FACES: Flat surfaces that make up the exterior form of a crystal.
FACET: Faceted Gems (gems with geometrically shaped flat polished
faces) and Non-Faceted Gems (those gems that do not have geometrically
shaped flat polished faces such as cabochons). Correct positioning and
angling of facets determines the amount of light that will reflect through
the gemstone.
FACETING: The polishing and cutting of the surfaces of a gemstone
into facets. The shape and number of the facets give the stone its style
of cut.
FANCY CUT: The name given to a gemstone that has an unconventional
shape after cutting.
FANCY DIAMOND: A colored diamond whose color is intense enough
to be a plus rather than a minus. Faintly colored stones are invariably
worth less than pure colorless ones.
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FIGARO: Similar to the "Curb" chain, but possessing alternately
sized links.
FILIGREE: A lace-like ornamental work created from intricately
arranged and intertwined wires.
FINDINGS: A general term used to cover a variety of semi-finished
components used in jewelry manufacturing such as settings, joints and
catches.
FINE GOLD & FINE SILVER:
The term used to describe precious metals in their purest forms i.e.,
unalloyed with no additions. Please refer to the
Precious Metals Buyer's Guide
for more information.
FIRE: This occurs when white lights splits into its constituent
spectral colors, the colors of the rainbow, when it passes through an
inclined surface, such as those on a prism or a faceted gemstone. Dispersion
in gems is called fire.
FLAW: A blemish or imperfection, either on the surface of a diamond
or in the interior. This may be in the form of a scratch, feathering,
carbon spots, etc. Bad color, proportion, and cut are technically not
considered to be flaws.
FLAWLESS: The highest clarity grade for a
diamond.
FLORENTINE FINISH: A crosshatched decorative technique engraved
into the surface of a precious metal. The lines are coarser and more deeply
incised than the "Brushed", "Matte" or "Finish" methods.
FLUORITE:
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FOLDOVER CLASP: A clasp where the hinged part opens, passes through
a ring and snaps shut holding the ring securely in place.
FOUR C's: Common trade term to collectively describe the major
considerations in a diamond's value: clarity, color, carat, and cut. FRACTURE:
This is when a gemstone breaks along lines of weakness related to the
internal atomic structure. Also referred to as cleavage.
GALLERY STRIP: A length of precious metal which
has been pierced to produce a continuous series of claws. Used for setting
large semi-precious stones.
COLOR CHANGE GARNET
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DEMANTOID GARNET: Click
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GROSSULAR GARNET: Click
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MALAIA GARNET: Click
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MALI GARNET: Click
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MANDARIN GARNET: Click
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MOZAMBIQUE GARNET:
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PYROPE GARNET: Click
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RHODOLITE GARNET: Click
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SPESSARTITE GARNET:
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STAR GARNET: Click
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TANGERINE GARNET: Click
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GEMSTONE: A decorative material, usually a mineral, treasured for
its beauty, durability and rarity. Commonly referred to as "gem" or "stone".
GEODE: Cavity within a rock, in which crystals line the inner surface
and grow towards the center.
GIRDLE: This is the band around the widest part of a cut gem, where
the crown meets the pavilion.
GOLD: Frequently featuring as an integral part of antique and
modern jewelry's numerous different forms, purchasers should be aware
of what gold varieties are on offer and why. Pure gold is relatively
soft and as a consequence unsuitable for use in jewelry. This
unacceptable tendency of pure gold has largely given rise to the
modern gold we find in the jewelers' window of today. Virtually all
gold featured in jewelry today is alloyed with secondary metals that
enhance its everyday durability. However, not all gold purities are
the same. The different purities of gold alloys used by jewelers give
consumers varying options regarding gold colors such as ROSE GOLD,
YELLOW GOLD & WHITE GOLD, their affordability and durability. Please
refer to the
Precious Metals Buyer's Guide for
more information.
Gold purity is measured in karats. While the term "karat" may sound identical
to the term "carat", which is used to measure weight in gemstones, the
two terms do not have the same meaning. Karat ratio in gold tells you
the percentage or proportion of gold purity. Gold with a higher karat
ratio, is comparatively more expensive gram for gram when compared to
gold with lower karat ratios. Expressed as a ratio of 24 parts, the most
frequently seen gold purities are: 24 Karat - 100 percent pure gold.
22 Karat - 91.7 percent pure gold.
18 Karat - 75 percent pure gold.
14 Karat - 58 percent pure gold.
10 Karat - 41.6 percent pure gold.
GOLD-FILLED: Also known as gold overlay. These terms refer to a
gold layer that has been bonded to a support metal. To qualify for use
of this term, the gold must be at least 10% of the total weight.
Gold-filled articles are similar to gold-plated; they have an exterior
of gold and a core of base metal, usually copper. The difference is in
the method of application. Plated objects are shaped and then
bullion-coated by electroplating, in which the soft gold takes the
object's form. Gold-filled merchandise is made sheets of metal to
which the outer covering of gold has been applied before the object is
shaped. Please refer to the
Precious Metals Buyer's Guide
for more information.
GOLD LEAF: Ultra thin gold plating that's pounded and thinned,
then applied to an object. Please refer to the
Precious Metals Buyer's Guide for
more information.
GOLD MARKS & STAMPS: Gold should always have a stamped "k", or
karat mark upon it that states its purity. U.S. law dictates that if a
karat mark appears, then you should be able to see the manufacturer's
trademark. In the U.S., nothing less than a 10 Karat purity can legally
be sold as gold, however in other countries 9 Karat and even 8 Karat gold
is legal. Please refer to the Precious Metals Buyer's Guide for more information.
GOLD PLATE: Means that a thin layer of gold plating that has
been bonded to a base metal. The total gold content of the object may
be less than 5%, must be properly identified in terms of total
content. Please refer to the
Precious Metals Buyer's Guide for
more information.
GOLD PRICING: Raw, un-worked gold pricing is based on the karat
ratio and the gold weight. For jewelry, we must also take into account
additional factors. Diamonds and gemstones must be accounted for, as
well as construction techniques that can make a piece of jewelry more
durable, more ornate, or even unique. Features such as robust clasps
all add to the price of a piece of finished jewelry. Please refer to
the
Precious Metals Buyer's Guide
for more information.
GOSHENITE: Click on
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G.P.: When found on an article that appears made of gold, these
letters indicate that the gold is merely surface plating
(gold-plated). Please refer to the
Precious Metals Buyer's Guide for
more information.
GRANITE: A coarse-grained igneous rock comprising mainly of quartz,
feldspar and mica.
GRANULATION: Minute metal beads, usually, used to decorate jewelry.
See ETRUSCAN.
GUILLOCHE ENAMEL: A translucent polychrome enamel placed on top
of a geometric engraved pattern on the jewelry or watchcase.
GUTTA-PERCHA: A plastic or rubber-like substance produced from
the natural fluids of certain Malaysian trees. When first introduced in
the 19th century, all forms of jewelry were produced from gutta-percha
as a novelty. It is dark brown in color and very brittle.
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