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Assay

The process by which an article is sampled, tested and marked to identify its precious metal content (see Hallmark).

Brilliance

The sparkle that a diamond displays, specifically the way in which white light is reflected back out of the top of the diamond.

Brilliant cut

A round diamond with 57 facets arranged precisely to create optimal brilliance.

Carat

One of the Five Cs, a diamond’s weight is expressed in carats; the greater the carat weight, the more expensive the diamond. One carat is equivalent to 200mg or 1/5th of a gram. The word ‘carat’ is derived from ‘carob’. In ancient India gems were weighed with carob seeds which are naturally uniform in weight.

Clarity

Another of the Five Cs, clarity assesses the internal and external perfection of the stone. All but the rarest diamonds contain inclusions, which are tiny natural imperfections in the structure of the stone. They are often not visible to the naked eye but may be viewable under magnification. The clarity scale runs from 'FL' (flawless) to 'I3' (marks visible with the naked eye).

Claw setting

Precious metal claws hold your diamond in place, ideally allowing the maximum amount of light into the diamond to enhance the beauty of your stone. A 4-claw setting features in our Classic engagement ring.

Colour

Another of the Five Cs, indicating how much colour tint is within a diamond. A white diamond should be as colourless as possible; however, since diamonds are a natural product, most stones have a trace of tinting. The scale runs from 'D – colourless' down to 'Z – strongly coloured'. E to J tints are rarely visible to the naked eye. Higher letters indicate yellow and brown tones.

Pink, blue, red, and green diamonds are also found, but are exceedingly rare and expensive: these are called fancy coloured diamonds. They do not follow the normal price scale for diamonds and are therefore priced separately.

Crown

The top half of the diamond, from the girdle to the table facet. A well-proportioned crown means optimal fire and brilliance in your stone.

Culet

The bottom point of the diamond. Sometimes tthe culet is faceted to reduce the posibilities of damage to the stone, however light can escape from the bottom of the stone. This is one of the many factors we look at when carefully selecting our gemstones.

Cushion cut

An antique cut in the shape of a cushion. It is a cross between an 'old mine cut' (deep cut with large facets) and an modern brilliant cut oval. It has fire and brilliance and makes the most of the diamond. A rare cut.

Cut

One of the Five Cs, the quality of the cut is crucial to the overall beauty of your diamond. Cutting a diamond takes time and great skill; an expert gem-cutter follows precise geometric rules to ensure optimally cut diamonds that sparkle. On a diamond certificate, cut is graded from 'poor', 'fair', 'good', 'very good' to 'excellent'.

Diamond Certificate

A document issued by one of several independent gemmological laboratoties to accompany your diamond. It contains an expert gemmologist's analysis of an individual diamond's dimensions, proportions, colour, clarity, symmetry, polish and other characteristics. The certificate guarantees your diamond's quality. You can view certified diamonds in our diamond database.

Emerald cut

A stepped, rectangular cut with cropped corners. It produces less fire and brilliance than a brilliant cut diamond. It is a beautiful cut where you can look deep into the heart of the stone.

Facet

The flat polished surfaces of a diamond. A round brilliant diamond has 57 facets; all facets are individually named.

Faceting

Another word given to ‘cutting’. The process in which a diamond's facets are formed by an expert gem cutter.

Fancy

A description used for diamonds of rare and desirable colours, rather than the more common yellow or brown tints. Fancy diamonds exhibit a pure tint of colours such as pink or blue, and are priced outside the usual scale for white diamonds. ‘Fancy’ is also used to describe cuts of diamond other than brilliant.

Fire

One of the most important visual qualities. Fire is created by the quality of the cut and refers to the spectrum of coloured light reflected out of the top of the diamond from within.

Flaw

An internal imperfection of a diamond (also referred to as an ‘inclusion’). There are many types of flaws, from ‘feathers’ to ‘clouds’, which are documented on the certificate for each stone. Not all flaws are visible to the naked eye. For more on how flaws are graded, see Clarity.

Fluorescence

Some diamonds exhibit a natural blue fluorescence under ultraviolet light. A much debated quality in a diamond, it can be desirable in the right quantities: fluorescence can enhance the colour of the diamond to be more white and in certain cases make it glow. It adds another layer of interest to the stone.

Girdle

The outer edge of the diamond, separating the crown and pavilion of the diamond. The girdle of a diamond is characterised by its thickness and whether it is faceted or polished.

Grain setting

Tiny beads of precious metal, precisely positioned to retain each stone. We have used grain setting in our Dress Collection.

Hallmark

Hallmarking, carried out by an Assay Office, involves assaying articles made of precious metal and marking them to indicate that they are of a minimum standard of purity. It is a legal requirement for all precious jewellery sold in the UK to be hallmarked. Hallmarks identify where the article was assayed (London, Birmingham, Edinburgh or Sheffield), who made it (maker's or sponsors mark), purity of the metal and usually the year of production of the article.

Inclusion

Any internal or external imperfection of a diamond, sometimes also referred to as a ‘flaw’. There are many types of inclusion, from ‘feathers’ to ‘clouds’, which are documented on the certificate for each stone. Not all inclusions are visible to the naked eye. For more on how flaws are graded, see Clarity.

Mount

The precious metal part of the jewellery without the stones, encompassing the head and the shank.

Mounting

The process of holding stones in the mount; also described as ‘setting’.

Oval cut

A brilliant cut diamond in the shape of an oval.

Pavilion

The bottom half of the diamond from the girdle down to the culet. The right proportions of the pavilion are crucial to the fire and brilliance of your diamond; too deep, too shallow and the light will leak out of the bottom of the stone making it look lifele.

Pear cut

A teardrop-shaped diamond with brilliant-cut diamond characteristics.

Point

An expression of weight of a diamond. One point is equivalent to 1/100th of a carat; a 0.75-carat diamond can be said to weigh 75-points.

Polish

The smooth finish on the facets of a diamond. Certificated diamonds are graded on the quality of their polish.

Princess cut

A square-shaped diamond with a cutting pattern designed to achieve great brilliance like that of a round brilliant cut.

Proportion

The relationship between the depth, table, girdle, symmetry, and pavilion angles. Perfect proportion is the aim of the cutter. Proportion influences light refraction and reflection, and therefore the quality of the cut.

Radiant cut

A rectangular shaped diamond with the characteristics of a brilliant cut diamond. The radiant cut was created to combine the emerald cut with a brilliant cut so that maximum fire and brilliance is exhibited.

Rub-over setting

A diamond set into the top of a precious metal collar with the edges pushed over to hold the stone in place.

Sparkle

The amount of light reflected from the diamond as it moves. It is the combination of fire and brilliance.

Shank

The part of a ring which holds the head in place; the bottom and lower side of the ring.

Shape

Shape describes the outline form of the cut (round or oval, for example). The two are often used together, e.g. round brilliant cut.

Symmetry

The overall uniformity of a diamond's cut. Symmetry applies to the pattern of the cut, not just the outline shape. The symmetry grade can go from poor to excellent. Poor symmetry will decrease a diamond’s sparkle because light leaks from the stone.

Table

The top facet of the diamond. Its size influences the proportions, fire and brilliance of the diamond.

Tension setting

An innovative setting by which stones are held in place using only the tension and pressure of the surrounding metal. This setting does not involve claws. Tension settings are featured in our Classic collection.

Total Internal Reflection

A measure of how well light travels into and back out of a diamond. When the facets of the stone are polished to the correct angles and ideal proportions, you achieve total internal reflection. This is found in diamonds with the highest grade of cut.