SAFETY CATCH
A safety catch is a secondary closure (usually on a fine bracelet or necklace) that is used in case the primary clasp opens, preventing the loss of the jewelry. It is often a hinged, snapping loop that is permanently attached to one side of the clasp (often a box clasp), and, when the bracelet is closed, snaps onto the other side of the clasp.

SAFETY CHAIN
A safety chain is a secondary closure (usually on a fine bracelet or watch) that is used in case the primary clasp opens, preventing the loss of the bracelet. It is usually a chain that is permanently attached to one side of the bracelet, and attaches to the other side with a spring ring clasp (or other type of clasp). On the Miriam Haskell cuff bracelet above, the safety chain is located on the lower left of the picture.

SAPPHIRE
Sapphire is a precious gemstone (a type of corundum) that ranges in color from blue to pink to yellow to green to white to purple (mauve sapphire) to pink-orange (padparadscha sapphire). Six-sided asterisms sometimes occur in star sapphires (caused by inclusions of tiny, thin, parallel needles of rutile). Sapphires are related to rubies. Sapphires were once thought to protect the wearer from poisonous creatures. Sapphire has a hardness of 9 and a specific gravity of 3.9 - 4.1. Sapphires are often heat treated to improve their color.

SAPPHIRE QUARTZ
Sapphire quartz (also called blue quartz) is another name for blue chalcedony.

SATIN FINISH
A satin finish on a metal is between a matte finish and a brilliant one. This semi-glossy finish is done by making shallow parallel lines on the surface of the metal, reducing its reflectivity.

SAUTOIR
A sautoir (also known as a rope) is a long necklace (longer than opera-length), often with an ornament (a tassel or pendant) at the end. Sautoirs were common during the Edwardian era.

SEED PEARL
Seed pearls are tiny, round pearls that are less than 2 mm in diameter and weigh under 1/4 grain. Seed pearl jewelry was popular from the mid- to late-Victorian era, when the tiny pearls were strung on horsehair to form intricate designs and were also used as accents on other jewelry.

SETTING
A setting is a method of securing a stone (or other ornament) in a piece of jewelry (or other object). There are many different types of settings, including the collet (a strip of metal surrounding the stone), the claw setting (in which prongs of metal hold the stone in place), Tiffany (a high,six-pronged setting), the cut-down setting (metal is worked around the edge of the gem, reinforced with metal ridges), pav?-set stones (stones set close together, showing no metal between them), millegrain (the stone is secured by small beads [grains] of metal), gipsy setting (with a recessed stone), and many other types (including combinations of the above-mentioned methods). Some settings are closed (there is metal behind the stone), while others are open (there is no metal behind the stone), letting light shine through the stone.

SHANK
The shank is the part of a ring that encircles the finger.

SHILLER
Shiller is coppery flakes within a stone. Layers of shiller can block reflected light, decreasing the stone's brightness. Sunstone and spectrolite often have shiller.

SIGNET RING
A signet ring is a ring that was used as a means of identification for relatively important people. The signet ring was engraved with a symbol (a coat of arms or initials) identifying a particular person. Some signet rings also had intaglio-carved seals. The earliest-known signet rings date from ancient Egypt, thousands of years ago.

SILVER
Silver is a fine, silver-white metal often used in jewelry. Pure silver has a hardness of 2.5. Other metals are alloyed with silver (usually copper) for silver used in jewelry making. Silver tarnishes after exposure to air (a thin layer of silver-oxide forms on the surface). Silver often occurs near copper lodes.

SLEEPER
A sleeper is a small hoop-earring made of gold that is used to keep the hole in a pierced ear open.

SLIDE BRACELET
(also called slide charm bracelet) A slide bracelet is a type of modern-day charm bracelet made from stringing Victorian era watch fob charms together on a double chain - the charms can slide along the chains. When pocket watches (used by men) and nceklace watches (used by women) went out of style after wrist watches were invented, the charms on the watch chain were removed and then strung together to make bracelets. Modern imitations are made using modern-manufactured charms.

SMOKY QUARTZ
Smoky quartz is a type of brownish quartz that has a smoky look.

SNAKE CHAIN
A snake chain (also called a Brazilian chain) is a metal chain made up of a series of small, linked cups.

SOLITAIRE
A solitaire is a ring set with a single stone, usually a diamond.

SPECTROLITE
Spectrolite is another name for Finnish Labradorite (a variety of plagioclase feldspar). It is a fairly abundant grayish mineral that has brilliant iridescent flashes of color (usually green, blue, orange, or red) after it is polished. The crystals are transparent to translucent. Spectrolite is usually cut with a flat surface in order to highlight the brilliant flashes of color. Spectrolite has a hardness of 6 to 6.5 and a specific gravity of 2.70.

SPECTROSCOPE
A spectroscope is an instrument that is used to identify gemstones. It works by determining the light waves that a stone absorbs; different stones absorb different wavelengths of light.

SPESSARTINE GARNET
Spessartine garnet (also called Spessartite garnet) is a type of a garnet that is orange (it varies from reddish orange to brownish orange to yellowish orange). The chemical composition is Manganese Aluminum Silicate. Crystals vary from transparent to translucent. This relatively rare gem is found in Sri Lanka, Australia, Madagascar, Brazil, Sweden, Myanmar, and the U.S. Spessartine garnet has a hardness of 7.0 - 7.5, a specific gravity of 4.19 (relatively heavy), and a refractive index of 1.8.

SPINEL
Spinel is a very hard semi-precious stone composed of octahedral crystals. Spinel ranges in color from red to black to yellow, frequently resembling rubies. Iron and chrome are components of spinel, giving it its color. Spinel belongs to the feldspar species and is found in in Burma, Sri Lanka and Thailand. Some varieties include: Balas ruby (red spinel), Almandine spinel (purple-red), Rubicelle (orange), Sapphire spinel (blue), Ghanospinel (blue), Chlorspinel (green). Spinel is also laboratory synthesized. Spinel has a hardness of 8, a specific gravity of 3.58-4.06, and a refractive index of 1.72.

SPLIT RING
A tightly-coiled ring used as an jewelry finding; it can attach charms to a charm bracelet or a clasp to a necklace or bracelet (it is like a miniature version of a keychain).

SPRING RING
A spring ring (also known as a bolt ring) is a hollow circular metal fastening ring with a spring opening. A tiny spring keeps the arm of this clasp closed. It is used to attach two other rings or links of a necklace or bracelet. The spring ring was invented early in the 1900's. Jewelry made prior to 1900 or so will not have a spring ring clasp.

SQUARILLION CUT
(SQUARE CUT) A Squarillion cut is a square-cut stone. This fancy cut is relatively new and is also known as a Princess or Quadrillion cut.

STABILIZED STONES
Stabilized stones have been impregnated with plastic to improve its durability, stabilize cracks, and improve the stone's appearance (a dye is sometimes added to the plastic - this is called a color shot or color stabilized). Liquid plastic resins are injected into soft, porous stone at high pressures - the plastic fills the pores in the stone. Turquoise is often stabilized.

STAR OF AFRICA
The Star of Africa (also called the Cullinan diamond) is the largest diamond yet found, weighing 3,106 carats (roughly 1.3 pounds) in its rough form. It was mined at the Premier Mine in South Africa in 1905. This enormous gem was named for the chairman of the company that owned the mine. It was given to King Edward VII of England for his birthday in 1907. The diamond was cut (by Joseph J. Asscher of Amsterdam) into many stones, including the Cullinan I (530 carats, pendelique-brilliant shaped, the largest cut diamond in the world), the Cullinan II (317 carats, cushion shaped), Cullinan III (94 carats, pendelique shaped), Cullinan IV (63 carats, square-brilliant shaped), and many other smaller stones.

STAR GARNET
A "star garnet" is almandine that exhibits an asterism. Almandine is a type of garnet that ranges in color from deep red to reddish-brown.

STAR RUBY
A "star ruby" is a ruby that exhibits an asterism, a six-pointed star of light (when cut as a cabochon). The world's biggest star ruby is the Rajaratna, which weighs 2,475 carats. The world's biggest double-star ruby (with a 12-pointed star) is the Neelanjali, weighing 1,370 carats.

STAR SAPPHIRE
A star sapphire is a sapphire that exhibits an asterism in the form of a colorless, six-rayed star that reflects light. Star sapphires are cabochon cut. Laboratory-produced star sapphires ("Linde stars") were developed in 1947 by the Linde company; most star sapphires today are synthetic.

STEP CUT
The step cut is generally used for colored stones. This cut is rectangular to square and has many facets parallel to the edges of the stone.

STERLING
Sterling is silver with a fineness of 925, that is, sterling is 925 parts per thousand (or 92.5%) silver and 7.5 parts per thousand (or 7.5%) copper (the copper increases the silver's hardness). Sterling is quite malleable.

STRASS
Strass is highly reflective glass that is made to imitate gemstones. The original rhinestones were quartz stones obtained from the Rhine river. These stones were cut to resemble gemstones.

STREAK
The streak of a mineral is its color when it is in powdered form. You can determine the streak of a mineral easily by rubbing a rough mineral (not cut stones!) along the surface of a hard, unglazed porcelain sheet (this is called a streak plate - you can use the back of a white porcelain bathroom tile). Even though the color of a mineral may vary, the streak color is constant. Note: the streak plate has a hardness is about 6.6, so it can only test mineral that are harder than that (since they must leave a streak on the porcelain). For example, the streak of chalcopyrite, graphite, magnetite, and pyrite is black, the streak of galena is gray, the streak of cinnabar, the streak of azurite and lapis is blue, the streak of malachite is green, the streak of turquoise is white with a green tint, the streak of olivine, amethyst, and tourmaline is white, and the streak of hematite is red-brown.

STRIATIONS
Striations are grooves, lines and scratches found naturally in some minerals.

SUGAR BEADS
Sugar beads are beads that look as though they were rolled in granulated sugar; the fine grains on the surface of the beads are in fact tiny grains of glass (or plastic). Delicate glass sugar beads were made in Gablonz and Japan early in the 20th century.

SYNTHETIC STONE
Synthetic stones are made in laboratories; these stones generally lack imperfections. They are very hard to distinguish from natural stones.