Diamond Guide

Clarity, Carat, Cut and Colour or the 4 C’s as they are more commonly known is how diamond buyers appraise diamonds. Each part of the 4 C’s plays a large part in the value of a diamond but also in a diamonds appearance.

Diamond appraising is a complex task with only very minor differences between grades which can only be determined using the relevant tools and under strict lighting conditions.

To try and simplify diamond appraising the 4 C’s are explained below in greater detail.

Diamond Clarity

Diamond Clarity is the term relating how many imperfections a diamond may have.

Imperfections within a diamond are called inclusions. A typical inclusion seen within a diamond could be a trace of non crystallised carbon or a very small crack.

Most diamonds have inclusions of some sort but to varying degrees. Quality diamonds will have inclusions that are only visible using magnification, but lesser quality diamonds will have inclusions that are visible to the naked eye. There are also some very rare diamonds that are totally free from inclusions.

Diamond clarity is graded using a jewellers loupe, which is a magnifying glass with a 10 times zoom.

The varying degrees of diamond clarity are graded using the scale below:

• IF - absolutely free from inclusions, no imperfections visible through a 10x loupe.
• VVS 1/2 - very very small inclusions, nearly invisible through a 10x loupe.
• VS 1/2 - very small inclusions, barely visible through a 10x loupe.
• SI 1/2 - small inclusions visible through a 10x loupe but invisible to the naked eye.
• P1 - inclusions immediately evident with a 10x loupe though hard to see with the naked eye.
• P2 - large/numerous inclusions visible to the naked eye and affecting brilliance.
• P3 - large/numerous inclusions very visible to the naked eye and affecting brilliance.

Engagement-Rings.co.uk only uses diamonds that have a minimum diamond clarity of SI1/2. The diamond clarity of SI1/2 offers fantastic value for money as it technically has small inclusions but these are not visible to an unaided human eye.

Diamond Carat

A carat is the unit in which a diamonds weight is measured.

The carat of a diamond is used to verify the exact weight of a diamond it is not used to determine a diamonds size. Therefore a two carat diamond is twice the weight of a one carat diamond, not twice the size.

One carat weighs exactly 200mg (milligrams).

Some jewellery is made up with more than one diamond and jewellery of this sort will have a total diamond weight. A total diamond weight simply equates to the total weight of all diamonds used in a piece of jewellery. A total diamond weight is not as valuable as the equivalent individual diamond weight.

Bigger diamonds have bigger prices, as the size of a diamond increases so does the rarity and cost. A two carat diamond is approximately four times the price of a one carat diamond of equal quality.

In order to give you an idea of what size a diamond is for a particular carat weight we have converted diamond carat weights into their approximate sizes in millimetres below.

Diamond Cut

Diamond cut is used to determine two things about a diamond.

Firstly diamond cut refers to the actual shape of a diamond (e.g. round, square, oval etc). A round shaped diamond is called a brilliant cut and a square shaped diamond is called a princess cut. It is the shape of a diamond that dictates how a diamond is actually cut and shaped by a diamond cutter.

Diamond cut is also a generalised term referring to the proportions, symmetry and polish of a diamond. These are the main factors which determine how well a diamond will sparkle and look aesthetically other than shape.

The symmetry of a diamond is how well aligned the facets of the diamond are. The main contributing factor in how well a diamond sparkles is how the light travels through the diamond. The light should enter the diamond and be reflected out at the top towards the person looking at it, not out of the side or downwards as a poorly cut diamond would.

The polish of a diamond is how smooth or rough the facets are. A poorly cut diamond will have rough and jagged facets, whereas a well cut diamond will have smooth facets that will similar to a well polished car have real depth and shine.

A final note about diamond cut is that a well cut diamond is often achieved at the expense of losing some of the diamonds weight, which is why bigger isn't always best.

Diamond Colour

Diamond colour is based upon a standardised scale set by The Gemological Institute of America. Every gemologist carries a set of master stones which means they can compare diamonds to determine a diamonds colour, this process is always performed under strict lighting conditions.

GIA’s diamond colour grading scale:

• Colourless - D, E, F
• Near Colourless - G, H, I, J
• Faint - K, L, M
• Very Light - N, O, P, Q, R
• Light - S, T, U, V, W, X, Y, Z

The rarest and most expensive of diamonds are the colourless ones, with diamonds becoming less expensive as the tint of colour increases. Diamonds above a colour H on the scale gradually become more tinted yellow in appearance.

A diamonds colour can also be affected by surrounding surfaces this is why a diamond is always graded for colour under strict lighting conditions. So a colourless diamond which has been set in a yellow gold setting will reflect some of this colour and even items of clothing such as that little red dress can change a diamonds appearance.

Premium Diamonds

On certain ranges we offer you the option to upgrade our standard quality diamond to a very fine quality diamond, diamonds for connoisseurs.

For a diamond to be considered a Premium Diamond it must meet our stringent grading criteria, diamonds are carefully reviewed by our gemologists before selection. Only the very best quality grade diamonds are appointed as Premium Diamonds.

Premium Diamonds simplified:

• Diamonds are cut by master craftsmen who liberate its fire, scintillation and brilliance.
• Exceptionally rare and valuable colourless diamonds; at least colour F.
• Clean of inclusions to the naked eye, barely visible through a loupe; minimum clarity VS2.
• Each diamond is independently certified by GIA, IGI, EGL or Anchor Cert.