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A to Z of Diamonds GlossaryClick here to return to FAQ IndexChard 24 Carat Home Page

Diamonds Index
Round Brilliant Cut Diamond
Round Brilliant Cut Diamond

A to Z of Diamonds Glossary
Alphabetical list of main words and terms relating to diamond or diamonds, containing over 600 entries, with definitions, explanations and links to more detailed information.

Table CutA simple, obsolete cut with one "slice" cleaved or polished from (usually) an octahedral. forming a table as on a modern stone.
Table FacetThe top and largest facet on most diamonds including brilliant cuts.
TacyTacy Ltd. Diamond Industry Consultants is a specialist strategic consultancy house and ‘think-tank’ exclusively serving the stakeholders in the international diamond industry. Publishers of Diamond Intelligence Briefs.
TangA tool or arm for holding a diamond while it is being ground or polished against a scaife.
Tension SettingA method of setting diamonds and other gems using only the springiness of the mount to hold the stone firm. Can look quite spectacular but rather chunky and heavy; insecure otherwise. Best avoided in our opinion, or use small unobtrusive underbezel to achieve similar effect.
Termite, TermitesProspectors have used termites, or their mounds to help detect diamonds. Termites burrow down to retrieve water, and carry back with them indicator minerals. Termite or Adam Ant?
TetrahedronHaving four faces. Tetrahedral is one of the crystal forms of diamond.
ThermoluminescenceThe property of diamonds and other materials to emit light when heated.
ThicknessUsually describing a girdle, and often expressed as a percentage of the height or depth of the diamond, often using relative terms such as "medium".
TiffanyThe name of a famous diamond, also a famous jeweller. Commonly used, presumably in breach of trade mark, for a particular style of diamond claw (prong) setting.
TolkowskyUsually referring to Marcel Tolkowsky who published his book "Diamond Design" in 1919, helping to revolutionise diamond cutting. Gaby (Gabi) Tolkowsky is also a famous diamond cutter.
ToneAn aspect of colour, important in grading fancy coloured diamonds.
TopThe part of the diamond above the pavilion, correctly called the "crown". Also a modifier used in descriptive colour grading systems, meaning better than or in the upper range of , e.g. top silver cape.
Top Light BrownA relatively lightly coloured brownish diamond, often bordering on white.
Top Silver CapeA diamond colour grade in obsolescent descriptive system, between commercial white and silver cape.
Top WesseltonA diamond colour grade in obsolescent mainly Scandinavian system, referring to a diamond of a colour at the top end of what could be expected from the Wesselton Mine.
Total CrapFamous words of Gerald Ratner, for which he will never be forgotten.
Total Internal ReflectionAn optical effect when light travelling in a higher refractive index material hits a boundary with a lower refractive index, and is reflected totally. Important when calculating diamond cutting angles.
Trading CompanyUsually referring to the "Diamond Trading Company", or DTC, part of De Beers.
Translate, TranslationTranslation of the word diamond into a number of other languages.
Transparent, TransparencyIdeally, a diamond should be completely transparent, any opacity is undesirable.
Trap CutAlso known as step cut. A traditional way to cut rectangular, octagonal or other non-round diamonds, including emerald cuts. Looses brilliance compared with more modern brilliant cut styles.
Treated, TreatmentIgnoring the fact that cutting and polishing of rough diamonds is a form of treatment, this usually refers to diamonds which have been processed in some way to enhance their colour or clarity.
Triangle, Triangular, Trilliant, TrillionA diamond which is three sided viewed from above. May be step cut or modified brilliant cut.
Trigon, TrigonsTriangular marks, usually small, and quite common on surfaces of rough and polished diamonds, due to twinning and other crystal growth factors.
Twin, Twinned, TwinningTwinning occurs when two or more crystals have formed together, where a single crystal has had a change in its crystal growth directions, or when negative crystal growth has taken place.
Type, TypesThere are two main "types" of diamond, type 1 containing nitrogen, and type 2 without significant nitrogen. Each type has two sub-types, A and B.

There are currently over 600 entries in this table.
Over 90 of them have page links to a page on this site. Eventually, we intend to add a more complete description for most entries, each on its own page. Please watch this space! the Lowest Possible Price

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