Aquamarine

A term used to indicate anything over 100 years old.

Art Deco

The artistic style and era that followed on almost immediately after Art Nouveau. It is generally accepted that the period was from 1910 to 1939, with its zenith in the 1920’s. It was characterised by the use of geometrical forms and extravagant colours in jewellery.

Art Nouveau

An artistic and architectural movement defined by among other things the use of wonderful, flowing and sinuous shapes. The jewellery was characterised by the use of precious and semi- precious gems, exotic enamelling, and the fanciful interpretations of naturalistic objects. In jewellery this movement only lasted from about 1895 to 1910.

Asscher-cut

A square step cut developed in 1902, known for its brilliance, fire and shape. This cut is normally associated with diamonds.

Baguette cut

A step cut gem, usually small, often used as a side or shoulder stone in rings. The shape of the cut gem resembles that of a long rectangle with a flat top.

Band width

The width in millimetres at the minimum point on the ring shank.

Brilliance

White light reflections from the surface and inside the diamond.

Brilliant cut

This cut gives the best balance of brilliance and fire for a diamond. The standard brilliant cut has 58 facets, 33 on the crown (top) and 25 on the pavilion (bottom). The brilliant cut includes round brilliant cut, square modified brilliant cut (princess cut), marquise, pear and cushion cut.

Cabochon

Generally refers to a gem cut in the shape of a dome. Often used with semi-precious gemstones.

Calibre

A term for measured gems. Normally applied to smaller sized gemstones.

Cameo

A carved gem in which the design stands out from the background.

Carat

Unit of weight for gemstones. Equivalent to one-fifth of a gram.

Channel set

A type of setting in which the stones are held in their place by pushing over a thin strip of metal on either side of the gem stone. This type of setting is often used in eternity rings or on the shoulders of more modern engagement rings.

Chenier

The name for a hollow tube. In rings, this is used to strengthen the shoulders of split hoops next to the centre collet.

Clarity

The purity of a gemstone.

Claw

The name given to the spike of metal that protrudes from the edge of the collet. These are bent over the edge of the gemstone to hold the stone in place. Solitaire rings often have either four, six or eight claws, while cluster rings may have more claws depending on the number of stones surrounding the centre gemstone.

Collet

A box or round setting surrounding the gemstone.

Coronet-setting

A claw setting in which the sides of the collet have been cut out to resemble a crown.

Crown

The upper part of a facetted gem.

Culet

The bottom facet of a brilliant cut stone.

Curtain collet

These are collets which resemble light curtain swags when viewed from the side.

Cushion cut

A modified brilliant cut, slightly square or oval in shape with rounded corners.

Dementoid

A garnet which is grass green in colour and often contains characteristic horse-tail inclusions.

Dispersion

This is the separation of the colours of the rainbow when light enters a diamond and other colourless gems. This play of colours is often referred to as fire or scintillation. The higher the optical dispersion of the stone, the greater will be the fire.

Edwardian

Although Edward VII reigned on the throne of Great Britain from 1901-1910, the period in jewellery lasted from 1901 until the outbreak of the First World War in 1914. The style was very much of an extravagant nature with an abundance of diamonds and platinum. Garlands and ribbons, light and finely made, characterized this style.

Edwardian cut diamond

See Old European Cut.

Emerald-cut

See Step cut with bevelled corners.

Engraving

The process in jewellery whereby metal is cut away, still leaving some of the original metal intact.

Eternity ring

A circular ring set with diamonds and/or gemstones.

Facet

A flat surface ground and polished onto a gemstone.

Fluorescence

The ability to convert invisible ultra-violet light into visible light. This is shown in diamonds that exhibit a bluish hue.

Fire

Flashes of colour visible in a polished diamond.

Gallery

The back of the bezel in a ring which is often decorated and gives strength to the ring.

Girdle

The edge of a polished diamond between the crown (top) and pavilion (bottom) sections. The girdle can be polished, unpolished or facetted.

Gold

A yellow precious metal used since antiquity to the present day in jewellery making.

Grain set

A type of setting in which the gemstone is held in place by tiny grains.

Half eternity ring

A circular ring in which one half of the band is set with diamonds and or gemstones.

Half hoop

A ring in which half of the hoop is occupied by gems, covering the width of the finger.

Hallmark

An official mark stamped on gold, silver, platinum and palladium to signify its purity or fineness.

Iridium

One of the platinum group of metals that is often combined in small amounts with platinum to be used in jewellery.

Lustre

This is the quality and nature of the light reflected from the surface of a gemstone. Diamonds have an adamantine lustre.

Marquise or Navette cut

A brilliant-cut which is boat shaped.

Millegrain

The term describing a metal edge that consists of tiny beads or grains. The technique is often used to set a gemstone or to form a decorative outer edge to a piece of jewellery. This technique came about in the nineteenth century and was a favoured method of the firm of Cartier.

Mixed-cut

A gem, usually a semi-precious coloured stone, in which the crown of the gem is brilliant cut and the pavilion (bottom of gemstone) is step cut.

Navette cut

A boat shaped, brilliant-cut gemstone.

Old European cut

Victorian and Edwardian cut stones can also be referred to as 'Old European Cuts'. These brilliant cut stones are typically round in shape with reasonable symmetry. They have deep pavilion facets, a high crown, and an open culet.

Old mine cut

Brilliant cut diamond with a flat table and cushion-shape used extensively in the mid to late eighteenth century and the early to mid- nineteenth century.

Palladium

A white precious metal, similar to platinum.

Pave setting

A setting method in which an area is covered with small stones like a paving effect with the smallest amount of metal between them.

Pavilion

The lower half of a gemstone below the girdle.

Pear cut

A pear shaped, brilliant cut gemstone.

Platinum

A white precious metal used extensively in jewellery from the beginning of the 20th century to the present day.

Princess cut

Square in shape, the princess cut, also known as the square modified brilliant cut, exhibits many of the characteristics of the modern brilliant cut diamond with an emphasis on brilliance and sparkle.

Radiant cut

A square diamond with brilliant cut facets and cut corners.

Refraction

The bending of light when it enters an optically denser medium such as a gemstone.

Rex collet

Collets that look like a crown when viewed from the side.

Rose cut

One of the very earliest of diamond cuts. The gemstone has a domed and faceted front and a flat back.

Rose gold

Also known as red gold, rose gold is produced by mixing gold with copper.

Round brilliant cut

a round diamond with 58 facets, cut for maximum sparkle and brilliance.

Rub over

A setting where a small collar of metal is pressed over the top-edge or girdle of the gemstone, which holds it securely in the collet.

Ruthenium

A precious metal used as a platinum alloy.

Scintillation

The sparkle you see when the diamond, the light or the observer moves.

Setting

The space where the gemstone is held.

Shank

The back of a ring hoop.

Shoulder width

The width in millimetres at the maximum point on the shoulders of the ring.

Sparkle

Like scintillation, this requires movement and is the total effect of light coming from the crown facets of the gemstone.

Square cut

See Step cut

Step cut

This cut has a large top facet, generally either rectangular or square shaped, surrounded by a series of step like trapezoidal facets. The lower half of the gem has similarly arranged trapezoidal facets. This type of cutting is very suitable for emeralds, sapphires, rubies and aquamarines.

Symmetry

When used in diamond grading reports, the term symmetry refers to the level of precision in cutting, shaping, and polishing the diamond. Perfect symmetry would mean that if an imaginary line passed through the centre of the crystal, then one side would be an exact mirror image of the other.

Table

The large flat facet situated at the top of a faceted gem.

Victorian

The era from 1837 to 1901, referring to the reign of Queen Victoria.

Victorian cut

Nineteenth century round brilliants with small tables and large culets and a deeper depth by modern standards.

Vintage

A term applied to items such as a piece of jewellery or a fine wine with either style or age.

White gold

A metal formed by mixing yellow gold with a white metal, usually palladium, to be used in jewellery.