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"Asscher-cut Diamond"
A diamond cut named by inventor, Joseph Asscher. In 1902 he developed a square cut diamond with 72 facets. With its wide step facets and deep clipped corners make the gemstone resembling an octagon.
"Baguette"
Is a type of gemstone cut that resembles long rectangles. "Baguette" meaning "rod" in French. Baguettes are very popular shapes often used on each side of a focal diamond.
"Birthstones"
A set of twelve gemstones that are associated with births during a specific zodiac sign or month of the year. Each stone chosen for each month vary by culture.
"Carat"
A carat is a measure of weight used for gemstones, and is equal to 200 milligrams. Weights are given to the nearest 1/100th of a carat, an amount which is called a "point." For example, a .50 carat gemstone might also be called one-half carat or a 50-point stone.
"Clarity"
A term used to describe the absence or presence of a gemstone's internal and or external flaws. The perfect stone with perfect clarity (clearness) is rare, although some flaws cannot be seen with the naked eye a jewelers loupe may be used for further magnification.
"Crown"
The crown is the portion of a cut stone that is above the girdle.
"Culet"
This is the tiny facet at the bottom of a gemstone. Not all gemstones have culets. A culet can help reduce the risks of damage to the stone.
"Cultured Pearl"
Cultured pearls grow inside a living organism similar to natural pearls. However, they do not begin as accidental intruders to the shell. Instead, humans insert mother-of-pearl beads or other shapes into a mollusk. Over time they become coated with nacre. Depending on how long the beads are left in place will determine the nacre coating.
"Diffusion"
Is the process of applying a temporary coating onto the surface of a gemstone in order to enhance its color.
"Doublet"
Referred to as a "gemstone sandwich' made in layered sections. The lower layer the larger portion, is made from glass or an inexpensive stone. The smaller layer of a more valuable stone adhered to the top of it. Opal doublets are most commonly used.
"Engraving"
Refers to inscribing a dedication or monogram to identify a piece, or create words of decorative motifs. The tool used is called a graver.
"Fluorescence"
Fluorescence is a characteristic that makes some diamonds appear to change color when they are exposed to the ultraviolet light.
"Fracture Filling"
Is a treatment that is used to fill-in tiny cracks in a gemstone with a clear, glasslike substance. This creates an illusion that makes them invisible to the naked eye. Fracture filling is not a permanent treatment.
"Fractures"
Interruptions on the surface of a gemstone that can show up as whitish areas because light does not pass through them as it does the remaining portion of the stone.
GIA Diamond Cut Classifications
The Gemological Institute of America (GIA) sorts diamond cuts into three basic categories.
- brilliant cuts
- step cuts
- mixed cuts
"Girdle"
The girdle is the edge formed where the top and bottom of a stone meet. The girdle is the area generally grasped by prongs when a stone is mounted into a setting.
"Gold Filled"
Jewelry or other items with a sheet of gold applied to its surface. Markings will indicate how much and what type of gold was used in the layer.
"Gold Plated"
A metal item that has a very thin layer of gold applied to it. The thin layer normally wears away more quickly than a gold filled item.
"Heat Treatment"
Commonly used to change or intensify the color of a gemstone. The stone is heated to a very high temperature, which causes the inclusions to reform themselves and improve the color by making either darker, lighter, more intense, or of a different color.
"Inclusion"
Is an internal flaw, bubble, cloud, graining, fracture, etc.. Inclusions are different from imperfections at the surface of the gemstone. Inclusions are not always bad. They can be used like a finger print, to identify diamonds and other valuable gemstones.
"Jet"
Jet is Black fossil coal or wood that can be easily carved into jewelry. Most jet is polished and some has an opaque appearance. Jet became fashionable for mourning jewelry in the nineteenth-century.
"Jewelers Loupe"
A loupe is a small magnifying lens, usually 10x magnification. This will enable you to take a closer look at a gemstone or other object. The loupe allows internal flaws and surface blemishes become more apparent and allows you to assess color, cut, and other important aspects of the stone.
"Karat"
The karat system is used to reveal the amount of pure gold found in an item.
- 24 karat (24K) gold is pure gold.
- 18 karat (18K) gold contains 18 parts gold and 6 parts another metal or metals, making it 75% gold.
- 14 karat (14K) gold contains 14 parts gold and 10 parts another metal or metals, making it 58.3% gold.
- 10 karat (10K) gold contains 10 parts gold and 14 parts another metal or metals, making it 41.7% gold. 10k gold is the minimum karat designation that can still be called gold in the US.
"Laser Drilling"
Laser drilling is a process used to remove inclusions (flaws) from diamonds, improving their clarity.
"Loupe"
A loupe is a small magnifying lens, usually 10x magnification. This will enable you to take a closer look at a gemstone or other object. The loupe allows internal flaws and surface blemishes become more apparent and allows you to assess color, cut, and other important aspects of the stone.
"Millegrain"
A millegrain is a style of setting in which the stone is held in place by a row of tiny beads along the girdle of the stone.
"Mother of Pearl"
The iridescent surface of the inside of certain shells. It is generally used to rich the appearance of watches.
"Natural Gemstone"
A gemstone formed in nature, which has not been touched by humans. It is a mineral, stone, or organic matter that can be cut, polished or treated for use in jewelry.
"Natural Pearl"
A natural pearl is a pearl that is created by nature. There are essentially three types of pearls: natural, cultured and imitation
"Organic Jewelry"
A gem type made by or derived from living organisms, such as pearls from oysters and amber from tree resin.
"Oiling"
Oiling is used as a sealant on a stone. This technique is commonly used on emeralds to improve clarity.
"Pavilion"
The pavilion is the bottom portion of a cut stone, beginning at the girdle and going to the point at its bottom end.
"Pavé Setting"
A type of setting where a number of small stones are set together. The stones are separated and held in place by little beads of the setting metal.
Inexpensive fashion pearls are not typically strung with knots between them.
"Prong Setting"
A prong setting, sometimes referred to as a claw setting, is the most commonly used gemstone setting. It is especially popular to display solitaires in engagement rings.
"Side Stones"
Side stones are chosen on the basis of design, never on the basis of trying to inflate carat weight. All side stones are chosen to compliment the center stone.
"Synthetic Gemstone"
A gemstone created by man in a lab. Synthetic stones often mimic the structure of natural stones. It can be very difficult for even an experienced gemologist to tell the difference between a synthetic stone from a natural stone.
"Table"
The flat top of a cut stone, sometimes referred to as its face.
"Trillion Shape"
This is a triangular-shaped diamond with 50 facets. Trillions are most commonly used as side-stones. (See side stones)
"Well Cut"
Proportions which ensure the maximum benefits between fire and brilliance. When natural light enters a properly cut diamond, it is reflected from facet to facet, and then back up through the top, exposing the utmost brilliance, fire and sparkle.
"Yellow Gold"
The only natural form of gold is yellow gold. Gold being so soft in its pure form, would normally be made into an alloy by mixing it with gold, copper and silver.
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