Engagement Ring Diamonds… Large or Small?

Large or small? What a question!

If you want a pink diamond for example, you may have to accept a small one; over 90 per cent of the worlds pink diamonds come from the Argyle mine in Western Australia, where the largest pink produced weighed 12.76 carats prior to cutting and polishing(less than 3 grams). The great auction house, Christie’s has had less than 20 polished pinks over 10 carats pass through their doors in nearly two and a half centuries! Pink diamonds are also extremely expensive. These and other fancy coloured diamonds will be discussed separately. This discussion is not exhaustive by any means but is a general discussion covering the basics of the four “C’s” (and how they may affect cost).

Size of diamond may be defined by the design of the final piece (maybe it is a piece that requires no large central stone, but is encrusted with the tiniest diamonds over the entire surface of the piece. Conversely you may want only a single stone (solitaire). Budget constraints may determine the ultimate size and quality of the diamond. If you do have budget constraints then you can get “more bang for your buck” (i.e. a larger diamond), if you are prepared to reduce all or some of the other qualities of the stone (colour, cut or clarity).

There is no real substitute for diamonds. They will retain their appearance year after year where other stones will invariably show signs of wear (scratches and chips). Other stones become dull in comparison to diamonds. A diamond will look as new even after it has been worn for generations.

Diamonds come in a wide range of carat (weight), cuts, colour and clarity; the 4 “C”s.

A carat is a unit of weight; one Carat equals one fifth of a gram. One carat is divided into 100 points; therefore a fifty pointer weighs half of a carat. The unit is expressed in numbers, with up to three figures after the decimal point. A one and a half carat diamond will be expressed like this; 1.50cts. A half point (the smallest size commercially available) is 0.005cts. The smallest facetted diamond ever produced (at this point in time 0.0003cts) is much smaller than this, but is not practical for use in jewellery.

This refers not to the shape, but to the quality of the cut (proportions, polish etc). I would suggest that you go for a good cut; close to ideal proportions. Unless you want to pay for the kudos, not many can tell the difference between very good and excellent. The proportions of the cut affect the stone’s ability to reflect the light that enters it, therefore affecting its “sparkle”.

Square cuts (princess, square radiant etc) should have equal table measurements, particularly if set on the diagonal. These stones will attract a premium over stones with very slightly unequal (rectangle, but so close to square that are visually square) table measurements, so a saving can possibly be made here.

This discussion refers only to white diamonds. Fancy coloured diamonds will be discussed separately.

White diamond colour is represented by letters alphabetically, beginning with the finest white stones at “D”. For colour, (in my opinion one of the most important aspects); anywhere from D (the whitest and most costly) through EFGH and I, but beyond that, (J,K,L etc) they are getting away from fine white and into tinted material – commercial grade. These colours may also be represented by letters such as O/W (off-white) and TLB (tinted light brown). This is what you might see at commercial jewellery chain stores.

In terms of clarity, diamond grading begins at iF (internally flawless – also very expensive) then continuing through; very, very slight inclusion 1 (VVS1), VVS2, VS1, VS2, Si1 (slight inclusion), Si2. These are all “eye clean”; the inclusions can only be seen under magnification. Beyond Si2 (“I” & “P”)these all have inclusions that are large enough to be seen with the naked eye and will more greatly affect the stones ability to refract light back out, making them dull in comparison.

Having said all that, then if you must work to a budget, I would suggest a minimum standard around a G-H-I colour, with clarity no less than si2 in a good (or better) cut. When you get up into “collection” quality (D-E-F colour and high clarity), you really start paying for the privilege.

Imperfect diamonds can now be laser drilled to remove large inclusions and be filled with a synthetic material. These diamonds can be a curse to the jeweller as they impose restrictions on fabrication processes on the jewellery bench.

Larger, quality diamonds are often laser-inscribed for identification purposes. These inscriptions, on the girdle of the stone, are microscopic and can only be read under high magnification.

If you want a perfect white diamond, it must be D in colour, internally flawless, cut to ideal proportions and completely natural; totally untreated.

 No Comments

Leave a Reply

Your email address will not be published. Required fields are marked *