All the different terms used in the jewellery world can be a little confusing, so we have tried to explain a few of them. If there is one we have missed, or you have any other questions, please click here to
ask an expert.
Alluvial
Gems or metals that have been separated by weathering from their host rock and are then deposited in rivers and streams.
Baguette
A gemstone cut in a narrow rectangular shape. A shape very popular in Art Deco jewellery.
Bezel
A stone setting in which a band of metal 'wraps' around the stones girdle or outside perimeter.
Briolette
A drop shaped stone, briolettes can be 'pear', 'heart' and 'tear-drop' shaped.
Butterflies
The component for pierced ears that holds the earring onto the ear by attaching to the pin. Also known as a scroll.
Cabochon
A smooth unfaceted gemstone cut with a domed top and a flat bottom. Usually round or oval.
Carat
A unit of weight used to measure precious stones. One carat is equal to 200 milligrams. Stones are measured to the nearest hundredth of a carat. There are a hundred points in a carat, therefore a .10 carat stone would be described as 10 points. Smaller stones are often referred to in points not percentages of a carat. The relationship between weight and size is different for each family of stones. Corundum (ruby, sapphire), for example, is heavier than diamond, therefore a one carat ruby is smaller than a one carat diamond.
Chatoyancy
Derived from the French chat ('cat') and oeil ('eye') it describes the phenomenon where light is reflected onto the surface of a stone creating a strip of reflected light, resembling a cats eye. Often seen in chrysoberyl, but also found in other gemstones including tourmaline and apatite.
Crown
The top half of a gemstone.
Cushion
A type of gemstone cut which is cushion like - square with rounded corners.
Dichroic
A gem that apears to be two different colours or shades when viewed from different angles.
Diffraction
The splitting of light into its spectrum of colours.
Emerald Cut
A stepped, rectangular gemstone-cut with cropped corners.
Enamel
Enamel is produced by fusing a glass 'paste' to a metal base to produce a glass-like, decorative surface.
Engrave
To carve, cut, or etch into metal with graver's tools, or to embellish with patterns using a stamping tool or drill.
Facet
One of the polished cut surfaces on a gemstone.
Faceted
A faceted stone has small, flat-cut surfaces that make a sparkling effect on transparent stones, sometimes translucent and even opaque stones are also faceted. The number and shape of facets determine the shape or 'cut' of the stone.
Filigree
This is a very fine and delicate technique used to produce detailed, intricate often swirling patterns out of metal.
Gold filled
14k Gold Fill as apposed to gold plating has approximately 100 times more gold on the surface. Gold filled, or rolled gold, looks and usually wears as well as karat gold.
Hallmark
A stamped mark applied to items of jewellery and silverware by the Assay Offices of Britain as a guarantee of authenticity. Consisting of four components: A sponsor mark, a standard mark (denoting the precious metal content), the Assay Office Mark ( London, Birmingham, Sheffield or Edinburgh) and a date letter with the year of hallmarking.
Inclusion
The natural occurance of solid, liquid or gaseous foreign matter contained within a gemstone. It can take the form of an air bubble, foreign object or even tiny crystals of another gemstone. Amongst collectors inclusions a often prized at they tell a story about the origins of the gem, add interest and are unique to each stone.
Iridescence
The way light reflects off the internal features of a gemstone. This gives rise to a play of rainbow like colours.
Karat
Karat, with a K is most commonly used in the United States, is the measure of the purity of gold. Measured at a ratio of 24 parts, called 'karats' ,therefore 24 karat gold is pure, while 9 karat gold is 9 parts of gold and 15 parts other alloy metals, mostly copper and silver.
Mohs' scale
The measure of the hardness of a mineral, relative to other minerals, based on the minerals ability to resist scratching. Never store gems higher and lower on the scale together as the harder one may scratch the softer.
Navette
A gemstone cut which is oval and pointed at both ends.
Opalescence
This is a milky blue form of iridescence.
Patina
The result of use and age on a surface. A rich patina on sterling silver and gold enhances its beauty over time and gives character to a piece.
Pierced
When metal has been cut completely through with a very small hole or fine detailed decoration.
Pleochroic
Describes a gemstone which appears two or more different colours or shades when viewed from different angles.
Schiller
A form of iridescene displayed in labradorite and moonstone.
Translucent
When light passes through a translucent stone it is scattered, so it is not possible to look directly through it. Rose quartz, prehenite and chalcedony are examples of this.
