The radiant cut is a method of cutting rectangular stones so that
they have the sparkle of brilliant cut round stones. The shape is
a rectangle with the corners clipped off - the length:width ratio
is usually from 1.5:1 to 1.75:1. This cut has from 58-70 facets; it
was invented in the 1970's. The top of the stone is emerald cut (with
about 25 facets above the girdle), but the bottom of the stone has
brilliant cut facets (with about 36 facets below the girdle).
Rainbow calsilica is a newly-found, multi-colored, layered stone
composed of calcium and silica. This stone has been recently used
for Zuni fetish carvings and in some jewelry (beads and cabochon
cut stones). Rainbow calsilica was only recently found in Mexico
or Northern South America (it's origin remains mysterious). Some
people theorize that this stone formed as a result of the runoff
of mining or oil-drilling chemicals, and has only formed in the
last 30 to 50 years (but this is uncertain).
Rainbow obsidian is another name for obsidian that is iridescent.
Rainbow opal is a type of precious opal that has curved bands of
colors (that resemble rainbows).
Rainbow topaz (also called mystic topaz or mystic fire) is topaz
that has been color enhanced by coating it with a fine layer of
metal atoms (in a process called vacuum deposition). This stone
has red, green, violet, and blue streaks. Mystic fire has a hardness
The Rajaratna is the biggest-known "star ruby" (a ruby
that exhibits an asterism, a six-pointed star of light, cut as a
cabochon). It weighs 2,475 carats.
A bezel that can turn clockwise or counterclockwise and clicks with
a ratchet action as it rotates.
The rati is an Indian unit of weight that is used for gemstones.
A rati is equal to 0.91 carats. The rati has varied in the past
(and in different regions).
The Raviratna is the biggest-known ruby. It weighs 3,600 carats.
Razza is a line of costume jewelry from the 1960s and early 1970s
designed by Luke Razza. Razza's pieces are highly collectible; they
are mostly figural (often depicting animals and signs of the zodiac)
and are generally large in scale. Many Razza pieces incorporate
plastic with the metal.
This is a term applied to stones which are made by using small chips,
powder and ground up low grade stones, binding or fusing them with
a plastic resin (epoxy) and compressing them into blocks. The blocks
are then cut into beads, cabochons, and slabs.
In some cases, the reconstituted stone is actually made from "real"
turquoise, amber, lapis or similar stone, but often the reconstituted
stones are nothing more than low grade rocks, like howlite, that
have been dyed and compressed to look like the real gemstone.
Ambroid is a form of reconstituted amber made from real amber pieces,
but is should be
classified as imitation because of the epoxy resin content. It is
made from scraps and shavings of amber that are heated and pressed
into large blocks. Insects found in ambroid are usually fully intact,
without broken body parts, as they were dead when added to the block.
Insects found in real amber usually have broken wings and legs caused
when they tried to escape from the sticky tree resin.
Reconstituted turquoise is manmade from pulverized pieces of turquoise
that are stabilized and compressed with plastic resins to which
dye is added and should be sold as "simulated" or "imitation"
turquoise. However, this form is often used in much of the mass
produced inlay jewelry.
A reconstructed stone is one that is made from pieces of smaller
stones or crystals). Reconstructed stones often have telltale air
bubbles. For example, "Geneva rubies" (reconstructed rubies)
are made from tiny ruby crystals that have been fused together.
This type of stone is generally no longer manufactured (except reconstructed
amber, which is stilll made) because synthetic stones are vastly
superior to reconstructed stones.
Red beryl is a is a rare, deep red variety of beryl. Gemstone-quality
forms of this mineral are found in only one place in the world,
in the Wah Wah Mountains, near Beaver, Utah, USA. Small crystals
of this gem were first found in 1905 in the Thomas Range in Juab
County, Utah. The mine bearing gemstone-quality red-beryl was found
in the 1950's. The biggest red beryl crystal ever found was 14mm
by 34mm, weighing about 54 carats. The average faceted red beryl
gemstone weighs about 0.15 carats. Red beryl has a hardness of 7
- 8, a specific gravity of 2.66-2.70, and a refractive index of
1.564-1.574. The chemical formula Be3Al2SiO6, with other trace elements.
Internal flaws in beryl gems can be hidden by treating the stone
with oil (this is often not disclosed to the buyer).
Red diamonds are rare, fancy diamonds and are quite valuable. Diamonds
are precious, lustrous gemstones made of highly-compressed carbon;
they are one of the hardest materials known. Diamonds have a hardness
of 10, a specific gravity of 3.5, and a refractive index of 2.417
See Rose Gold.
An opaque, rust-red color of jasper.
When light enters a medium with a different optical density (like
a gemstone), the light is bent at an angle (and also changes its
The refractive index is a measure of how light is refracted in a
substance (like a gemstone). In doubly-refractive stones, the light
is split into two light rays when it enters the stone, and the rays
travel in different paths - so these stones have more than one refractive
A refractometer is a device that measures the refractive index of
A material with a high melting point, which makes it useful as a
barrier between the heat source and a material that you don't want
to melt, like the sides of an oven, etc..
Regard jewelry uses the stones Ruby, Emerald, Garnet, Amethyst,
Ruby, and Diamond to spell the word "REGARD." Regard jewelry
was given as a token of affection. This sentimental style was popular
during the Victorian era.
A kind of decoration that protrudes from the surface, like a cameo.
The period in western Europe from the mid fifteenth century to the
industrial age. The word means "rebirth" and was characterized
by a radical development in the arts, medicine, politics and sciences.
Renoir of California
"Renoir of California" is a US jewelry company that makes
copper jewelry. Their line marked "Matisse" is enameled
copper; their line marked "Renoir" does not have enamel.
The enameled copper leaf pin above is marked Matisse adn was made
by the "Renoir of California" company.
Repousse is a method of decorating sheet metal in which designs
are hammered into the back of the metal. Special punches are used
to form the designs, which form in relief (raised designs) on the
surface of the metal.
A type of luster exhibited on gemstones like amber.
Used in the jewelry making process to create a textured surface
with ridges, ripples and valleys. The process requires deft use
of a torch to bring the metal to a high
temperature just below its actual melting point. The jeweler carefully
moves the torch flame around the metal surface, "pulling"
the almost flowing metal into various ridges.
This takes extreme concentration and patience, allowing the torch
to remain directed in one area for a split second too long will
cause the metal to melt and either form a hole or a "ball"
of molten metal instead of realizing the desired effect. The pattern
of valleys and ridges of a reticulated piece is unpredictable and
trying to duplicate a pattern is impossible although a skillful
craftsperson will be able to create something similar for perhaps
an earring set.
Retro jewelry is chunky, geometric jewelry from the 1940's. Pink
gold was often used in retro pieces.
Reverse Crystal Jewelry
(also called Essex crystal) A clear crystal is cut as a cabochon.
A carving is made on the flat side, like an intaglio, and painted
with a thin layer of mother of pearl to produce a three-dimensional
Reverse-carved lucite is lucite (a transparent plastic) that is
carved on the back side. The incised areas are often painted, highlighting
the carving. The pin pictured above is clear, reverse-carved lucite
that is accentuated with yellow and green paint; the painted carving
closely resembles tiny roses.
Rhinestones are highly reflective glass made to imitate gemstones.
The original rhinestones were quartz stones (rock crystal) obtained
from the Rhine river. These stones were cut to resemble gemstones.
The best rhinestones today are made of highly reflective leaded
glass which is faceted and polished. The Trifari pin above has baguette
cut and round cut rhinestones.
Rhodium is a white precious metal. Rhodium is extremely expensive
and is often used to plate precious and base metals, giving jewelry
a hard, platinum-like sheen.
Rhodochrosite is a mineral whose color ranges from rose to pink
to almost yellow or brown. Although it is very pretty, this stone
is soft and brittle; it is used in jewelry and for carvings and
figurines. Rhodochrosite is Manganese Carbonate; its chemical formula
is MnCO3. Rhodochrosite has a hardness of 3.5 - 4.5 (glass has a
hardness of 4) and a specific gravity of 3.5. Rhodochrosite is found
in Argentina, Peru, Germany, Mexico, South Africa, Russia, Italy,
USA (Colorado and Montana), and Romania. Rhodochrosite is not enhanced.
Rhodolite (meaning "rose stone" in Greek) is a purple-red
to pink-red variety of garnet. It is a combination of almandine
and pyrope (it is sometimes called pyrope-almandine garnet). This
silicate stone has a hardness of 7-7.5 and a specific gravity of
3.5 - 4.3. The formula for garnet is: A3B2(SiO4)3. Rhodolite is
found in the US, Zimbabwe, Kenya, and Sri Lanka (Ceylon). Rhodolite
is not enhanced.
a glassy, opaque, pink to rose-red mineral, often with black inclusions,
composed of crystalline manganese silicate. Named after the Greek
word "rhodon" meaning "rose". It is found in
the former Soviet Union, the U.S., India, and Australia and is usually
used as an ornamental stone.
Resembling a prism with six four-sided facets.
An undulating ridged texture, like a person's rib cage
showing through the skin.
Richelieu jewelry is made by Joseph H. Meyer Bros. company of Brooklyn,
N.Y. THe Richelieu name was first used in April, 1911. Richelieu
manufactures clips, rings, necklaces, bracelets, and other costume
A ring is a piece of jewelry worn around the finger; rings have
been worn on every finger, including the thumb. Rings have been
worn through the ages, and often have significant meaning. Some
rings include wedding and engagement rings (denoting commitment),
signet rings (impressed with the owner's seal), bands (made from
a ribbon of metal), rings denoting group membership (like Masonic
rings or college rings), devotional rings (with religous meaning),
and pugilist rings (pointed rings worn by boxers to harm their opponent).
A ring worn above another ring to keep it from slipping off the
Rings are sized using a graduated cone (a mandrel) with markings
denoting the ring sizes. The ring is put on the cone and its size
is read where it fits snugly on the cone. To size a finger, a finger-ring
gauge is used. The rings are marked with their size and the person
determines which one fits well. Another, less accurate method, is
a cardboard card with cut-out holes marked with the ring sizes.
Sizes in the US and Europe are numerical; sizes in the UK are alphabetical.
To determine the ring size of a finger using the circumference of
the finger, or to determine the size of a ring given its diameter,
the formulas are:
System Formula using Circumference Formula using Diameter
USA Circumference in mm = 36.107 + (2.5890*Ring Size) Diameter in
mm = 11.4931 + (0.8241*Ring Size)
Europe Ring Size =Circumference in mm Ring Size = 3.1416 * Diameter
UK Circumference in mm = 36.667 + 1.2368*Ring Size(where 1=A, 2=B,
etc.) Diameter in mm = 11.6713 + [0.3937 * Ring Size(where 1=A,
A method of joining two flat objects together by making a hole in
each piece, then passing a pin with a large flat head, (composed
of the same metal as the piece), through the holes. The pin is then
pounded flat to secure it in place. This process was used in jewelry
instead of soldering when it was not advisable to use heat or when
one part was intended to swivel.
Riverstones are smooth, rounded pebbles found in rivers and on beaches.
The action of the water and other rocks on riverstones polishes
them naturally. Riverstones can be used as beads/stones in jewelry.
A necklace composed of a single strand of gemstones of the same
size and cut, usually Diamonds.
"Robert" and "Original by Robert" were costume
jewelry marks used by the Fashioncraft Jewelry Company (founded
by Robert Levey, David Jaffe, and Irving Landsman in the 1942. These
high-priced, hand-made pieces are often complex, having beads and
pearls, rhinestones, enamel, and/or floral designs; they are often
similar to some Miriam Haskell pieces. Robert jewelry was used in
some Hollywood films, including the 1952 movie "Viva Zapata."
Robert pieces were produced until around 1975.
Rocaille is jewelry whose design is based on sea life, sea shells,
Rock crystal is a transparent, crystalline mineral. Rock crystal
is the purest form of quartz and a semi-precious stone.
Rocky Mountain Ruby
A Rocky Mountain ruby is actually a pyrope garnet (and not a ruby
Rolled gold is a very thin sheet of gold that is laminated to a
lesser metal (usually brass). The two layers of metal are heated
under pressure to fuse them together. The sheet is them rolled into
a very thin sheet and then used to make jewelry or other objects.
Jewelry made from rolled gold wear well over time. Rolled gold pieces
are marked rolled gold plate, R.G.P., or plaqué d'or laminé.
Rolo Link Chain
A chain composed of individually linked round or oval rings resembling
a standard cable chain, but with thicker rings.
A round metal disk, sometimes studded with stones, that is strung
on a necklace as a spacer between beads.
A rondelle is a small disc used as a spacer in beadwork. Some rondelles
are clear crystal discs, often used between colored crystal beads.
Other rondelles are encircled with chanel-set diamonds or rhinestones.
A rope is a string of pearlsthat is over 40 inches long.
A series of small oval-shaped links that are arranged
in such a way that they make a spiral design resembling woven rope.
Rose de France
Rose de France is a recent name for a very pale variety of amethyst.
It is also known as lavender amethyst. Rose de France has a hardness
of 7.0. This pale lilac transparent gem is found worldwide and is
a type of quartz. Rose de France is sometimes heat-treated in order
to lighten its color and/or to remove smokiness.
The rose cut (also called the rosette cut) for diamonds was invented
in the 17th century and its used continued until the 18th century.
The rose cut has a flat base and triangular facets (usually 24).
This cut has little wastage of stone, but is not nearly as reflective
as the brilliant cut, which was invented later.
Jewelry finished so that it has the look of Rose Gold, but no actual
Rose gold (also known as pink gold) is gold with a pink tinge. It
has been alloyed with a mix of 90% copper and 10% silver.
Rose quartz is a form of quartz that ranges in color from pink to
A bezel that can be turned to perform different timekeeping and
See Axis of Symmetry.
Rough stones or crystals are in their natural state, they are neither
cut nor polished.
Roulz is a metal alloy that consists of about copper, nickel, and
silver. Ruolz is named for the French chemist and musician Vicomte
Henri de Roulz, who invented the alloy in the 1800s.
Round Brilliant Cut
See Brilliant cut.
Rubellite (sometimes spelled rubelite) is a red variety of tourmaline.
Rubellite is red in both incandescent light and daylight, and is
more valuable than other varieties of red tourmaline. Rubellite
has a hardness of 7-7.5 and a specific gravity of 3.02-3.25. Rubellite
is sometimes treated with fillers to increase the clarity of the
Rubies are precious stones and a member of the corundum family (Al2O3).
Rubies range in color from the classic deep red to pink to purple
to brown. Rubies are extremely hard; only diamonds are harder. During
the renaissance, people thought that rubies could counteract poison.
Laboratory-produced rubies were created in the 1890's; they are
difficult to distinguish from natural rubies. The biggest ruby in
the word is the Raviratna, which weighs 3,600 carats. Rubies have
a hardness of 9 and a specific gravity of 3.9 - 4.1. Rubies are
found in Afghanistan, Australia, Brazil, Cambodia, India, Myanmar
(Burma), Malagasy Republic, Malawi, Pakistan, Sri Lanka (Ceylon),
Tanzania, Thailand, United States, and Zimbabwe (Rhodesia).
A ruby spinel (or spinel ruby) is deep red, transparent spinel (not
Rumanite is a type of opal that is from Romania.
Russian Gold Finish
A Russian gold finish is a matte, antique-look finish. Miriam Haskell
jewelry often has a Russian gold (plated) finish.
Ruthenium (abbreviated Ruth or Ru) is a precious metal that belongs
to the platinum group of metals. In jewelry, ruthenium is added
to platinum alloys; about 5 to 10 perent ruthenium can be added
to platinum to harden and strengthen the alloy. Ruthenium's atomic
number is 44.
Rutilated quartz is a type of rock crystal which contains long,
fine needles of rutile crystals (titanium dioxide). This beautiful
stone is usually cut as a cabochon. It is also known as Venus' Hair
Stone, Cupid's darts, and Fleches d'amour (arrows of love).