A to Z of Diamonds Glossary

Diamonds Index

Round Brilliant Cut Diamond

Dahlia Cut	One of a number of "flower cuts" developed by Gaby Tolkowsky in about 1997 for De Beers.
De Beers	Dominant diamond mining and marketing company since the nineteenth century, believed to have a near world monopoly, together with various subsidiaries and group members.
Deep	Usually meaning a diamond which has been cut too deep which maximises weight, but sacrifices brilliance. Also refers to deep mines.
Depth	The height of a diamond from top to bottom, table to culet.
Density	Density is defined as the ratio of the mass of an object to its volume. The density of diamond is 3.52 grams per cubic centimeter.
Detection	A reference to the ability to detect diamond simulants, synthetics, and treatments.
D, D. Colour	D colour denotes colourless on the GIA scale.
Diagem	Diagem is a Canadian diamond exploration, production, and marketing company. The name diagem has also been used for a diamond simulant.
Diamantaire	French for "diamond-cutter", person or company who polishes diamonds.
DiamantKring	An Antwerp club and meeting place for dealers mainly in rough diamonds.
Diamonaire	An imitation diamond (simulant), composed of CZ.
Diamond	Diamond is an isomer of carbon. The word diamond is often used incorrectly to describe a lozenge shape. The diamond in baseball refers to the infield or the whole pitch, so named because of its lozenge shape.
Diamond Amendment Bill	A proposed South African law to give the state control over its diamond deposits.
Diamond Bank	The Diamond Bank (Switzerland) Ltd. was founded in Geneva in 1982 with the aim of further developing the financial needs of the international diamond and jewellery community. It is majority owned by KBC which also owns Antwerp Diamond Bank.
Diamond in the Rough	An expression meaning somebody or something having exceptionally good qualities or the potential for greatness but lacking polish and refinement.
Diamond Jubilee	The diamond jubilee is often stated as the seventy fifth (75th) anniversary, but a diamond jubilee is generally recognised as the sixtieth (60th) anniversary.
Diamondoid	Diamondoids were first discovered and isolated from Czechoslovakian petroleum in 1933. They have the same internal carbon structure as diamond crystals. Diamondoids include adamantane, diamantane, triamantane & tetradiamantane.
DiamondPlus	A piece of equipment developed by De Beers primarily to detect HPHT enhancement of natural type 2 diamonds.
Diamonds	The plural of diamond. Other meaning include the name of one of the four suits in playing cards, the third-highest ranking suit in contract bridge. Diamonds is also the title of a 1975 movie (film) with Robert Shaw and Shelley Winters, and a 1999 movie with Kirk Douglas and Dan Aykroyd.
Diamonds from Sierra Leone	A rap song by Kayne West using audio sampling from Diamonds are Forever. There are at least two different sets of lyrics, all of which sound as if they might mean something, but probably don't.
DiamondSure	A piece of equipment developed by De Beers to enable rapid screening of Type 2 diamonds including synthetics, so that they can be further tested.
DiamondView	A piece of equipment developed by De Beers to help distinguish type 2 CVD synthetics, most of these show orange luminescence in ultraviolet light, although it is possible to produce high quality ones which exhibit little or no orange luminescence. Most natural type 2 diamonds show blue luminescence.
Diamond Wedding Anniversary	The diamond wedding anniversary is often stated as the seventy fifth (75th), but a diamond jubilee is generally recognised as the sixtieth (60th) anniversary.
Diamonique	A proprietary brand of imitation diamond, usually made of Cubic Zirconia (C.Z.), owned and marketed by QVC.
Direction	Direction is important in diamonds and most gemstones for a number of reasons. Hardness is directional as it depends on "grain" direction. The optimal direction of cutting and polishing also depends on the optical axes of many stones including some diamond simulants.
Dirty Diamonds	A new song and album by Alice Cooper. Also refers to conflict diamonds, keeping diamonds clean, and a book.
Disclosure	The ethical and legal requirement to disclose to any purchaser, any treatment or process which a diamond has undergone, rendering it anything but completely natural.
Discount, Discounts	If you are prepared to haggle, and pay cash, you can get a discount at almost any retail jeweller. Our prices are already at fully discounted cash and carry prices.
Discovery	Modern diamond discovery is carried out by geologists employed by exploration and resource companies, usually be searching for kimberlite pipes.
Dispersion	Dispersion is the ability of a diamond or other gemstone, to differentially refract light of different wavelengths (colours), thereby splitting apparently white light into spectral colours. Fire. Diamond has very high dispersion at 0.044, which is one of the factors making it an ideal gemstone.
Dop	A holder for diamonds while they are being cut and polished, originally made of solder, modern ones are controlled by computer to enable further mechanisation, and accuracy of shape.
Double Diamond	"Double Diamond" is an American skiing term for an extreme, expert-only ski slope, designated by a sign with 2 black diamonds. Also known as a double black diamond. Double Diamond is also the name of an English beer.
Double Refraction	Although diamond is normally singly refractive, many gemstones are doubly refractive (bi-refringent), and diamonds can also be doubly refractive because of internal strain or inclusions.
Draw, Draws, Drawing	In diamond dealers' jargon, a diamond which is not pure white (colourless) is often said to draw colour.
Dresden	The name of the largest known green diamond.
Drill, Drills, Drilling	It is now possible to drill neatly into a diamond using a laser. This is most often done to remove dark stains of iron oxide within inclusions, but could also be done to create a diamond bead.
Drill Bit	Because of its hardness, diamond is often used in high quality or high performance drill bits.
Durable, Durability	Diamond is one of the hardest, toughest, and most durable of substances.
Dust	Very small rough diamonds used as abrasives, also called diamond powder.
Dutch Rose	A style of rose cutting with 24 facets on the crown, sometimes 6 large, and 18 smaller.

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!