Grey edge of a facet, sometimes referred to as chipping in severe cases. The facet edge should be sharp and clean.
Unforeseen worsening of quality during the manufacturing processes, usually in the form of internal cracks appearing, or existing cracks becoming bigger, resulting in a loss of value.
A category of regular customer introduced in 2015. Accredited Buyers must have the same standard of financial probity as Sightholders but do not need to commit to the same level of spending.
Mining for diamonds that have been carried by wind and water down rivers over millions of years.
Bachelor of Arts.
Rectangular in shape, with stepped faceting. A simplified Emerald cut.
The Broad-Based Black Economic Empowerment programme is an economic policy initiated by the South African Government aimed at providing priority economic development opportunities for previously disadvantaged groups in the mainstream economy.
Bachelor of Accounting Science.
Fine feathers or vezels around the edge of the girdle, often occurring during the bruting process.
The promotion of in-country wealth creation and skills development by supporting diamond-related activities in producer countries.
Main facets on the crown of the stone.
A diamond polisher that specialises in putting the first facets on a diamond.
A light shaping by polishing of the rough diamond to suggest the final model.
Very low quality diamond, usually used for industrial purposes. Can be crushed to powder and mixed with fine oil to form a paste and then applied to the scaife.
Liquid used to coat the stone while polishing, which protects it from burning.
Sixteen bottom halves positioned each side of the pavilion main facets.
A meeting place where diamond dealers meet to transact business; a trading floor.
A dark area across the centre of a fancy shaped stone, common in oval, marquise and pears, detracting from value.
Best Practice Principles: a set of ethical, social and environmental guidelines by which all De Beers operations and De Beers Sightholders operate.
The intensity of the reflections/fire coming from the diamond.
The most popular cut for a round stone, 58 facets. Round Brilliant Cut.
The polishing of the stars and halves that gives the stone its brilliance.
A polished model normally exploiting a whole stone. Regular triangular facets are arranged over the whole surface of the rough. Resembling a bead and often drilled at one end for threading.
Crumbling surface on a stone.
Bachelor of Science/Bachelor of Science in Mechanical Engineering (also, BEng).
The shaping of the girdle by rotating one diamond against another.
Made by the scaife on the surface of a facet due to excessive heat or an uneven surface, generally caused during the brillianteering stage. Caused by the iron reacting with the diamond under heat.
The four main characteristics that define the quality of a polished diamond: carat, colour, cut and clarity.
Compound annual growth rate, a year-on-year percentage growth rate over a specified period of time.
To slightly alter or correct the orientation of a facet. As in cantle the table.
A unit of mass for diamonds and gemstones, standardised worldwide in the 20th century at exactly one-fifth of a gram (the metric carat). One of the 4Cs.
The number of carats in an individual piece of jewellery.
A steady state in which mining operations are suspended, though the ability to resume in the future is maintained.
A grading report issued by a Gemmological Authority detailing and pronouncing on a stone's colour/quality/make and size.
A small or shallow opening usually on the girdle edge or a smaller sized cleavage (<1.8cts).
A stone's relative position on a flawless to imperfect scale.
Part of the dop, which holds and supports a stone during the polishing process.
The splitting of a stone along the cleavage plain into two or more pieces.
A type of business model indicating online and offline sales operations, involving a website and a physical store.
Term normally applied to the cheaper qualities of rough, which need to be split before further processing.
Term used to describe high colour rough and polished.
A diamond’s colour is a result of its composition: colourless diamonds allow more light to pass through than a coloured diamond.
The completely automated recovery plant, or CARP, treats diamond-containing ore.
Mined rough diamonds used to fund rebel and revolutionary activities against legitimate and internationally recognised governments.
Two diamonds that roughly match, to form a pair for a piece of jewellery, such as earrings.
Cracks are filled with a clear substance to enhance the stone's appearance.
An old and stable part of the continental lithosphere that may contain diamonds. Having often survived cycles of merging and rifting of continents, cratons are generally found in the interiors of tectonic plates.
Specially prepared areas on the scaife, ie for blocking or brillianteering.
The upper part of a polished diamond.
The facet at the point of the pavilion on a polished stone (if present); the pavilion point itself (if the facet is absent); the general region of the pavilion point.
The proportions and finish of a polished stone. Cut can also mean make.
The process of preparing a rough gem-quality diamond so that it can be used in the manufacture of jewellery.
Chemical Vapour Deposition: a process to create synthetic diamonds.
A machine designed to create synthetic diamonds using the CVD process.
De Beers Global Sightholder Sales.
A device used in the recovery plant to separate the diamondiferous material from waste.
Diamonds are heavier than the material that surrounds them. Once the ore has been crushed to a manageable size, it is mixed with a slurry made of finely ground ferrosilicon prepared to a specified density. In the method known as Dense Medium Separation that exploits the relative densities of different materials, we apply centrifugal force to separate out a diamond-rich concentrate.
Diamond Engagement Ring.
The French term ‘diamantaire’ (‘diamantair’ in Flemish) is used in the diamond industry to denote a person who possesses diamond-related skills.
A precious stone consisting of a clear and typically colourless crystalline form of pure carbon, the hardest naturally occurring substance.
A body of rock or other mineralisation containing a concentration of diamond of possible economic interest.
The allure that diamonds have for consumers on the basis of their association with romance and a sense of the eternal, and the fact that they are seen as a lasting source of value.
Containing or yielding diamonds.
The Diamond Insight Report is an annual written report first published by The De Beers Group of Companies in 2014. The report aims to summarise the outlook and trends across the diamond pipeline.
Jewellery containing diamonds, no matter how big or small, including in combination with other precious or semi-precious stones.
Diamond jewellery received as a gift or self-purchased.
The industry value chain that runs from consumers and retail stores to jewellery manufacturers, cutters and polishers, back to producers and explorers.
The sellback or trade-up of previously owned diamonds or diamond jewellery.
A direct economic impact arises from the initial increase in economic activity (eg the GVA generated, the additional employment created and the taxes that are contributed to public finances).
Attached to the end of a tang, adjustable to angle facets, also holds a pot for the diamond to sit in.
The process of measuring physical, chemical and structural properties of penetrated geological formations using logging tools that are either lowered into the borehole on a wireline cable (wireline logging) or placed just behind the drill bit as part of the drill pipe itself (logging-while-drilling).
The stage of the diamond value chain that includes jewellery retailing to end consumers.
Diamond Trading Company Botswana.
Earnings Before Interest and Tax: an indicator of a company’s profitability, calculated as revenue minus expenses, excluding tax and interest.
The polishing stage just prior to brillianteering. Small sizes can be sold in this state, and called eight cuts.
Used in relation to the Indian consumer market, the terms refer to consumers according to their annual household income levels: SEC A/B non-Elites – between US$5,000 and US$35,000; Elites - between US$35,000 and US$70,000; Super Elites – above US$70,000.
Traditionally a cut-cornered, rectangle in shape, but can be square. The facets are elongated and of various sizes.
Payments to Government arising from payment of remuneration to employees, including wages, salaries and bonuses.
Unpolished areas left on the stone indicating yield has been maximised.
Cut A round brilliant cut made to a high standard of make and finish.
Polished on to a stone to reduce or hide an imperfection.
Flat faces on diamonds. These can be naturally occurring or can be created in the polishing process.
Any usual colour outside serie, eg pink, brown, green, blue, orange or dark yellow.
Any shape or cut except a round brilliant.
Another word for crack.
A ferroalloy which is an alloy of iron and silicon.
Jewellery made with precious materials, such as gold or precious and semi-precious stones.
Flashes of different spectral colours in diamonds, as a result of despertion, reflection and refraction; scintillation.
The narrowest measurement taken on a stone to determine maximum polished diameter.
A general term used to refer to any internal or external characteristics.
A stone with no internal inclusions or surface blemishes when viewed at 10x magnification.
Reaction of a diamond to ultra-violet light. Detracts generally from value in high colours, but can increase value in low colours. Caused by impurities within the atomic lattice.
FTEs represent the number of people who work on a full-time basis, where persons working less than full-time hours represent a proportion of an FTE determined by the percentage of full-time hours typically worked.
At Jwaneng Mine, this is one of the most modern and secure automated recovery and sorting facilities in the world. Its principal advantages are increased security and reduced recovery costs.
Forevermark is the diamond brand from The De Beers Group of Companies. Only one per cent of the world’s diamonds are of sufficient quality to have the Forevermark icon (invisible to the naked eye) inscribed on them. De Beers also sells diamonds via De Beers Diamond Jewellers, an independently managed joint venture with LVMH Moët Hennessy Louis Vuitton.
Graduate Diploma in Engineering.
A cut and polished precious stone fine enough for use in jewellery.
A rough or manufactured precious stone fine enough for use in jewellery.
Gemological Institute of America: a US-based non-profit organisation established in 1931 engaged in research, gem identification and grading services as well as a variety of educational programmes worldwide.
The edge of a diamond, at the widest part. It can be polished, faceted or bruted.
An instrument to draw around the girdle during manufacture to ensure the correct placing of top and bottom facets.
Term used to describe the appearance of a polished stone that has little 'life' usually due to the bottom angles being too flat. Also describes rough crystals.
A crack, sometimes called a feather.
Term used to describe the number of carats found per 100 metric tonnes of rock in the recovery process.
Direction for polishing, cleaving, sawing.
Normally refers to smaller stones whose weight is expressed in grains rather than carats (particularly rough stones weighing less than 2.79 carats and polished stones weighing less than 1 carat); in the Diamond Trading Company, ‘grainers’ refers to stones weighing more than 3 grams but less than 2.79 carats. Stones that are smaller than this are sometimes colloquially referred to as ‘smalls’.
Government of the Republic of Botswana.
GDP is a basic measure of a country’s overall economic output. As an aggregate measure of production, GDP is equal to the sum of the gross value added of all residential units (ie industries) engaged in production, plus any taxes, and minus any subsidies, on products not included in the value of their outputs.
GVA is a measure of economic activity. It is often referred to as the ‘income from production’ and is broadly equivalent to the wages and profits generated by a particular economic activity, or total output (revenues) minus intermediate costs. GVA differs from GDP in that it does not include net taxes and subsidies levied on products.
There are 16 top halves: facets put around the edge of the crown and 16 bottom halves.
A variation of a round stone. A 'V' shaped groove is made in the edge of the stone to give the heart shaped appearance. The width is approximately equal to the length.
Round Brilliant made to precise proportions. The facets appear through the table as eight arrows and from the bottom, eight hearts.
Eight main facets (four top/four bottom).
Preferred in Hong Kong/China for the larger table. Usually in medium to low colours and good quality.
High Pressure High Temperature: a process to create and treat synthetic diamonds.
Form of round brilliant professing to have ideal proportions. First branded by Lazar Kaplan.
The International Institute of Diamond Grading and Research is the part of De Beers that offers polished diamond grading services and through which De Beers’ diamond verification instruments are sold.
IBAs are formal contracts outlining the impacts of the project, the commitment and responsibilities of both parties, and how the associated Aboriginal community will share in benefits of the operation through employment and economic development.
Inclusions are very easily seen through the table with a 10x loupe; they can also affect the brilliance of the stone. The first quality where inclusions can be seen with the naked eye.
Any naturally occurring material inside a diamond (including internal cavities and cracks).
A natural that penetrates the surface of the stone.
Single stand-alone stores as distinct from retail chains of multiple stores.
Minerals used to help locate diamond deposits. They are minerals that are characteristic of kimberlite but usually more abundant than diamonds (and therefore easier to find). Indicators form in association with diamonds in the kimberlite and are scattered over a wide area by erosion. By tracing these indicators, the source of the kimberlite may also be found.
As producers increase their output, there will be an increase in the demands they place on their suppliers, which continues down the supply chain.
As a result of the direct and indirect effects, increased employment results in an increase in household incomes throughout the economy. A proportion of this increased income will be re-spent on final goods and services, thus generating further economic impacts.
Natural diamonds and synthetics used for non-jewellery purposes in manufacturing processes across various industries (oil and gas, precision tools, mining etc).
Abbreviation for the currency Indian rupee.
Area in a stone with a deformed crystal structure, associated with plastic deformation; can effect translucency.
If stones have no internal inclusions only slight surface blemishes visible under 10x loupe.
A diamond, coloured stone and jewellery certification organisation established in 1975 with headquarters in Antwerp.
Term of rounds popular in Japan for their smaller table. Normally made in good colour and quality. Usually polished for 'excellent' proportions.
Pieces cleaved or lasered from a larger stone.
A 'V' shaped groove made in a rough diamond originally by hand using another diamond, or lasered on a cleaving grain, prior to splitting the diamond in two.
Intergovernmental rough diamond certification scheme aimed at preventing conflict diamonds entering the legitimate diamond value chain.
An intrusive igneous rock that is sometimes diamondiferous. It is unevenly grained, containing minerals such as olivine, phlogopite and pyrope garnet, cemented with a groundmass consisting of minerals such as serpentine, calcite and chromate. Kimberlite occurs in the earth’s crust in vertical structures known as kimberlite pipes.
A kite-shaped facet is formed from a bezel after the star and top half facets are made.
Bachelor of Laws.
Master of Laws.
A magnifying glass, usually magnifying 10 times (10x). A ‘hand loupe’ is hand-held, whereas a ‘head loupe’ has two lenses (one for each eye, providing stereoscopic vision) mounted on a frame worn on the head. For practical reasons, the standard magnification for a diamond sorter’s head loupe is 3.5x rather than 10x.
A recovered rough diamond greater than 0.5mm.
Master of Business Administration.
A term used to describe small cut and polished diamonds. The diamond weight for melée diamonds ranges from as low as 0.001 carats (1,000th/carat) to 0.18 carats.
A very small rough diamond, less than 0.5mm.
The stage of the diamond value chain that includes sales of rough diamonds, cutting and polishing, primary and secondary sales of polished diamonds, and jewellery manufacturing.
A diamond formed naturally over millions of years in the earth’s crust.
A quality band between gem quality and industrial diamonds.
Okavango Diamond Company.
Onsite contractors represent indirect employees working at a particular mining site.
Mining from the surface to expose the ore below.
The lower part of a polished gem, below the girdle.
Payments in respect of taxes, including both taxes borne and taxes collected.
The geological period lasting from about 2.6 million years ago to 11,700 years ago.
Diamonds that have been polished in preparation for use in jewellery manufacture.
Polished Wholesale Price: a term referring to prices achieved by cutter polishers in cutting centres for polished diamonds.
Mineral deposits that can be economically extracted.
Temporary mismatch between supply and demand caused by the de-stocking or re-stocking activities of midstream operators in response to changes in market conditions.
Return On Invested Capital: the return on invested capital measure gives a sense of how well a company is using its money to generate returns. Comparing a company’s ROIC with its cost of capital reveals whether invested capital has been used effectively.
A diamond that has been mined but not yet cut and polished in preparation for use in jewellery manufacture.
Royalties and mining taxes refer to payments to Government in relation to revenue, production or profit generated under licence agreements.
A sales event where customers can inspect and buy diamonds from De Beers.
Term contract rough diamond customers of De Beers.
A substance used to imitate diamond.
Colloquial term for rough diamonds under three grainers. A grainer is a unit often used in the diamond trade to approximate the weight of a rough diamond; a grain is about 0.25 carats.
An in-vehicle Event Data Recorder that makes constant video recordings of a journey. It is designed to reduce risk by encouraging safe driving behaviour and aiding in the process of investigating car accidents.
Social investment refers to social contributions paid on a compulsory or voluntary basis, either from allocated budgets or established programmes.
An item of jewellery (for example, a ring) that highlights a single diamond.
The process of classifying rough diamonds into a variety of categories based on their natural characteristics, specifically their colour, clarity, carat and model or shape.
A man-made diamond with the same chemical composition, crystal structure and physical properties as its natural counterpart. Where a product is man-made, but has the same structure as a natural counterpart, an accepted description must be used to make clear that the product is man-made. Synthetic is one such description.
The largest, central octagonal facet on the crown of a polished diamond.
Any non-natural processes (other than shaping, polishing and surface cleaning) that change, interfere with and/or contaminate the natural appearance, composition or durability of a gemstone. For diamonds, this includes colour treatments (and decolourisation or ‘bleaching’), fracture filling, laser-drilling, irradiation treatment, and coating.
Often used in relation to China and India, this term relates to key characteristics of a city, particularly its population, economic development, regional GDP, transport systems and infrastructure, and/or historical and cultural significance.
A synthetic diamond that has been falsely passed off as a natural gem.
The stage of the diamond value chain that includes rough diamond exploration and production.
Flemish for surface crack.
VS stones have imperfections that are not easily seen. Small clouds and feathers are typical.
VVS stones have slight imperfections that are difficult to see. Imperfections would be only visible from the pavilion or small enough to be removed by repolishing.
Weighted Average Cost of Capital: a calculation of a company’s cost of capital in which each category of capital is proportionately weighted. All capital sources – common stock, preferred stock, bonds and any other long-term debt – are included in a WACC calculation.
Wages typically relate to employment based on hourly rate of pay, while salaries are typically agreed on an annual basis. This means salary payments do not tend to vary based on short-term (eg weekly/monthly) fluctuations in hours worked, while wages would.
A flemish word meaning grain: either sawing or cleaving.
An organisation that buys polished diamonds in order to distribute them to jewellery manufacturers and retailers.
Very small facets polished on to the rough diamond to see more clearly into the stone.
The weight of a polished stone achieved from the rough normally expressed as a percentage.
In polishing it is flat on the three point grain. A facet can not be polished on this grain.
Smoothing of a facet on the scaife to a mirror finish.