Diamonds explained

What you need to know about buying a Diamond.

‘GIA Certificated available on request’

‘Magic Sizes’

Carat weights known as ‘magic’ sizes signify a price increase once reached.

These are:

1/2ct – 0.50ct

3/4ct – 0.75ct

1ct – 1.00ct 

1.5cts – 1.50ct

2cts 2.00ct

Under-sizes are diamonds that weigh just below a ‘magic’ size. In choosing a diamond which is slightly ‘underweight’ it is often possible to save money e.g. in choosing a diamond weight of 0.95cts, opposed to the magic size of 1ct. As carat is a measure of weight and not strictly size, it is possible that the two stones can appear to be the same ‘size’ when seen in direct comparison, though one is shy of a magic size as one diamond might spread more than another.

How to choose a diamond for an engagement ring:

Define your budget and spend as much as you are comfortable with. I can provide you with assistance to help maximise your budget.
To create an engagement ring it’s vital to consider finger size; remember that slender fingers can make small diamonds look bigger.
Consider lifestyle, will the ring be worn and seen on a regular basis?
Think about what sort of setting will hold the diamond, these will also determine the style of the engagement ring. Are you looking for something plain or something a little more extraordinary?
Find out what size diamond the person wearing it may be expecting.

The 4 c’s Carat, Clarity, Colour, Cut. 


Diamonds are weighed in carats with one carat weighing about the same as a paper clip, or 0.2 grams. Just as a pound is divided into 100 pennies, a carat is divided into 100 points which means that a diamond of 50 points weighs 0.50 carats. But two diamonds of equal weight can have very different values depending on their clarity, colour, and cut. Carat weight is the most intuitive of the 4Cs – you expect a larger diamond to be worth more.


Because they are created deep within the earth, most diamonds contain unique birthmarks called inclusions (internal) and blemishes (external). Diamonds without these clarity characteristics are rare – and rarity translates to higher cost when purchasing diamonds. Using the GIA Diamond Grading System, diamonds are given a clarity grade that ranges from Flawless to Included (I3).

I can supply certificated diamonds on request. The un-certificated stones I supply are also specifically chosen for colour G/H/I and clarity around VVS – SI.

You can substantially reduce the cost of a diamond if you see that the inclusion will be hidden behind the mounting and not affect the overall appearance of the stone.

YYou can get excellent value with diamonds which have ‘Slight Inclusions’ (grades SI1, SI2, SI3).

We only sell diamonds with a clarity grade of SI1 and higher.

What clarity grade is best?

FL (Flawless) is the best clarity grade and therefore the best to buy, it is also the most valuable grade of clarity.

The average person can’t tell the difference between FL and VS1 clarity diamonds, to ensure the diamond is free from visible inclusions (eye clean) you will need a VS1 or VS2 clarity grade.

Many people believe that all diamonds with SI clarity grade are eye clean, but this is not strictly true. There can be visible differences between two diamonds with the same SI clarity grade, and this will depend on the number, type, size, and location of the inclusions.

Types of clarity flaw

There are 2 types of flaw:

Inclusions are flaws within the stone itself such as air bubbles, cracks, and non-diamond minerals; blemishes are surface flaws such as scratches, and pits.

For the purposes of grading diamonds, all flaws are called ‘inclusions’. Diamonds are graded for clarity under 10 to 30 times magnification. Grades range from ‘Flawless’ (completely free of blemishes and inclusions), to ‘Included 3’ (diamonds which possess large, heavy blemishes and inclusions that are visible to the naked eye).

Flawless Perfect inside and out. No inclusions or blemishes visible to a trained jeweller, even under high magnification.

Internally Flawless Absolutely no inclusions inside of the diamond. Only very slight surface blemishes, most often from when the stone was cut, visible only to a trained jeweller under 10x magnification.

VVS 1 or 2:
Very Very Slight inclusions VVS1 takes a trained jeweller 10x magnification to detect the smallest inclusion which are extremely difficult to see. The same with VVS2 but only slightly easier to find. Not visible to the naked eye.

VS 1 or 2:
Very Slight inclusions VS1 the inclusions are still invisible to the naked eye and are still somewhat difficult to find under 10x magnification. VS2 the inclusions are invisible to the naked eye but are now easy to see with magnification.

SI 1:
Slightly Included, Inclusions can now be seen with the naked eye but they are very tiny.

SI 2:
Slightly Included, Inclusions are small, but now easy to see with the naked eye.

I1 or 2:
Included, Numerous inclusions through a large amount of the diamond, most of which are quite obvious.

Included, Very included. The inclusions are large and very obvious. The number of inclusions could cause the diamond to be structurally weaker.


Most diamonds found in jewellery stores run from colourless to near-colourless with slight hints of yellow or brown. The only exceptions are the fancy-colour diamonds that lie outside of this range.

The whiter and more colourless a diamond is, the greater its value.

D-F – Colourless – naturally the most valuable and desirable because of their rarity.
G-I – Virtually no discernible colour visible to the untrained eye.
J-M – Very faint hint of yellow will be apparent however, this can be minimised by selecting the right mount.
K-Z – Visible colour tint.



It seems miraculous that the traditional 58 tiny facets in a round cut diamond, each precisely cut and sharply defined, may be only two millimeters in diameter. But without this precision, a diamond wouldn’t be near as beautiful as it is. Without a doubt, the allure of a particular diamond depends more on cut than anything else.

What makes a well–cut diamond?

A well-cut diamond will have angles which allow light to reflect into the eye of the person looking at the stone.

When a diamond is well cut, and viewed face-on, light enters through the top of the stone where it reflects from one side to the other before bouncing back out of the diamond to be seen by the viewer’s eye. This light is called the ‘brilliance’.

In a poorly cut diamond, light entering the diamond ‘leaks’ out from the sides or bottom rather than reflecting back to the eye.

The less light reflected back into the eye, the less brilliance a diamond emits.