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 of 8.
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
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
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
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 - 2.419.
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 speed).
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 index.
A refractometer is a device that measures the refractive index of a gemstone.
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
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"
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 effect.
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
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,
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
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 jewelry.
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 finger.
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 in
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, 2=B, etc.)]
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
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, or
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 at all).
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 gold
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 deep
A bezel that can be turned to perform different timekeeping and mathematical
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 stone.
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 a
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).