This is a heat treatment process which softens material that has hardened during rolling or drawing processes.
This is a gemstone, often a diamond, cut in a narrow rectangular shape. Small diamonds cut this way are often used as accents.
An item used as a mount between the ring shank and the setting, available in different sizes to match the individual settings.
A method of setting gemstones in which the stone is held in the mounting by a narrow band of metal surrounding the girdle (outside perimeter) of the stone.
A tear-drop shaped stone in the round.
A component used in the manufacture of earrings for pierced ears. It holds the earring onto the ear by attaching to the pin. It can also be known as a scroll piece.
A gemstone cut with a domed top and a flat bottom. These are usually round or oval, but can be other shapes as well.
A unit of weight measurement for precious stones. It is important not to confuse this with ‘karat’, which is a measure of the purity of gold. ‘Carat’ is abbreviated to "ct." One carat is equal to 1/5 of a gram (200 milligrams). Stones are measured to the nearest hundredth of a carat. There are a hundred points in a carat, so that a .10 carat stone can also be described as a 10 point stone. Smaller stones are most often referred to by point designations.
An average one-carat round diamond usually measures approximately 6.5mm in diameter. This relationship of weight and size, however, is different for each family of stones. Rubies and sapphires, for example, are both heavier than diamonds, so a one carat ruby or sapphire is smaller in size than a one carat diamond.
This word is derived from the French words chat (‘cat’) and oeil (‘eye’) and describes the phenomenon whereby a strip of light is reflected onto the surface of the stone and glints back and forth, resembling the feline eye. It is most prominent in chrysoberyl, but is also found in a few other gemstones including tourmaline.
The top half of a gemstone.
This can be a type of diamond cut incorporating both a round and square shape (therefore resembling a cushion). It also refers to a style of signet ring stamping, which is also cushion-like, being square with rounded corners.
This is the stepped, normally rectangular gemstone-cut with cropped corners.
Loosely speaking, all enamel is produced by fusing coloured powdered glass ‘paste’ to metal (usually bronze, copper or gold) to produce a glass-like, decorative surface. The colour of the enamel and its transparency depend on the metal oxides in the glass and the temperature at which the glass melts and coheres to the surface. In some cases, the enamel may be translucent with fancy engraving on the metal underneath, which produces guilloche (pronounced ‘ghee-yosh’) enamel.
This is gouging out a design in metal with graver's tools, or embellishing metal or other material with patterns using a stamping tool or drill. This was fashionable in mid-Victorian jewellery. The resulting depressions were often filled with coloured enamel.
The polished face of a gemstone.
A faceted stone has small, flat-cut surfaces that make a sparkling effect on transparent stones. Diamonds, rubies and sapphires are nearly always faceted. Some translucent and even opaque stones are also faceted, although this is rarer.
This is a technique used to produce delicate, intricate patterns in metal. It is often used for metal beads and clasps.
This is a unit sometimes used to measure pearls – a metric or pearl grain is equal to 50 milligrams or ¼ of a carat.
Routed out in a line.
This is a stamped mark applied to items of jewellery and silverware by the Assay Offices of Britain as a guarantee of authenticity. The mark consists of four components: The sponsor (or manufacturer) mark; the standard mark, which denotes the precious metal content of the item; the Assay Office Mark (Assay Offices are found in London, Birmingham, Sheffield and Edinburgh) and the date letter which shows the year in which the article was hallmarked.
This is a particle of solid, liquid or gaseous foreign matter contained within a stone. It can take, for example, the form of an air bubble or a foreign object. Some inclusions decrease the value of a stone, but some, such as needles in rutilated quartz and ‘spangles’ in amber, are prized.
This is when a space is routed out of the metal and a contrasting material is fitted into that space. Bakelite polka dot bracelets are an excellent example of inlay technique.
This is an optical phenomenon in which the hue on the surface of the stone changes according to the angle from which the surface is viewed. A similar phenomenon may be seen on the surface of soap bubbles and on butterfly wings.
The word is derived in part from the Greek word iris, meaning ‘rainbow’, from the goddess Iris, the personification of the rainbow in Greek mythology.
This is a semi-finished product used in the manufacture of brooches or any item which includes a pin for fastening. The joint holds the pin at one end allowing it to swivel for opening and closing.
This is a magnifying glass used by jewellers to see the inclusions and imperfections inside gemstones.
In this phenomenon, the material appears yellowish-red in transmitted light and blue in scattered light. The phenomenon is named after the appearance of opals.
This can be seen in nature in the way the sky is blue in the daytime and yellowish-red at sunset.
This is a pre-metric unit of weight. The unit used to measure gemstones is known as a ‘troy ounce’. The metric equivalent of one troy ounce is 31.1035 grams.
The lower-half of a gemstone.
This is when the material has been cut completely through with a very small hole.
This is the phenomenon where many different colours are displayed within one stone.
The ‘flecks’ in the iridescent colour display found in labradorite and moonstone.
A component used in the manufacture of earrings for pierced ears. It holds the earring onto the ear by attaching to the pin. It can also be known as a butterfly.
This is a very small round pearl. These were strung on horsehair and used in intricately woven jewellery during the early-mid Victorian period and are still popular in fine jewellery today.
This is a style of signet ring, usually stamped, where the head has been pierced to take a semi-precious stone. Onyx is commonly used for this.
Translucent stones allow light to pass through them, but the light is scattered, so it is not possible to look directly through. Translucent stones include moonstones, opals and carnelian.
Transparent stones allow light to pass through them without scattering, so that it is possible to see right through them. Transparent stones include diamond, zircon, emerald and ruby.