Everything you need to know about diamonds

Diamonds, set as earrings, diamonds set as a bracelet, diamonds set as a necklet, diamonds set in rings, in fact all diamond set jewellery has been used for centuries as a store of wealth, and whenever you have a store of wealth you have collateral for a pawnbroking loan.

get a pawnbroking loan against your diamond ring

The diamonds themselves are judged traditionally on what is know as the 4 C’s. Carat weight , Colour, Clarity and Cut. Although more recently a fifth C- Certificate- has become a vital way of ensuring that you have what you were sold.

CARAT WEIGHT of your Diamond

Diamond carat weight is the measurement of how much a diamond weighs. A metric “carat” is defined as 200 milligrams.

Each carat can be subdivided into 100 ‘points.’ This allows very precise measurements to the hundredth decimal place. Sometimes when describing the weight of a diamond is below one carat it is often referred to by ‘points’ alone. It can also be referred to as a fraction. For instance a diamond that weighs 0.25 carats is often described as a twenty-five pointer, or as ¼ carat. Diamonds weighing greater than one carat are usually expressed whole numbers and decimals shown to two decimal places.

All else being equal, diamond price increases with diamond carat weight, because larger diamonds are more rare and more desirable. But two diamonds of equal carat weight can have very different values (and prices) depending on three other factors of the diamond 4Cs

It’s important to remember that a diamond’s value is determined using all of the 4Cs, not just carat weight.

CUT of your Diamond

Diamonds are renowned for their ability to transmit light and sparkle intensely. We often think of a diamond’s cut as shape (round, emerald, pear), but a diamond’s cut grade is really about how well a diamond’s facets interact with light.

Precise artistry and workmanship are required to fashion a stone so its proportions, symmetry, and polish deliver the magnificent return of light only possible in a diamond.

A diamond’s cut is crucial to the stone’s final beauty and value. And of all the diamond 4Cs, it is the most complex and technically difficult to analyze.

To determine the cut grade of the standard round brilliant diamond – the shape that dominates the majority of diamond jewellery –the laboratory carrying out the certificate calculates the proportions of those facets that influence the diamond’s face-up appearance. These proportions allow the assessor evaluate how successfully a diamond interacts with light to create desirable visual effects such as:

Brightness: Internal and external white light reflected from a diamond

Fire: The scattering of white light into all the colours of the rainbow

Scintillation: The amount of sparkle a diamond produces, and the pattern of light and dark areas caused by reflections within the diamond

The diamond’s cut grade also takes into account the design and craftsmanship of the diamond, including its weight relative to its diameter, its girdle thickness (which affects its durability), the symmetry of its facet arrangement, and the quality of polish on those facets.

Standard round brilliant diamonds in the D-to-Z diamond colour range contains 5 cut grades;


Very good




The most popular cuts being

Round brilliant cut diamond

Princess cut diamond

Marquise cut diamond

Pear cut diamond

Cushion cut diamond

Emerald cut diamond

Ascher cut diamond

Radiant cut diamond

Heart cut diamond

CLARITY of your Diamond

Inclusions and blemishes are structural imperfections which affect the clarity grading of diamonds. Inclusions are largely crystals of diamond or a foreign material that has formed within the stone affecting the internal composition, while blemishes are flaws which affect the stone’s surface. The size, number, colour, location, orientation, and visibility of inclusions and blemishes are all taken into account when evaluating the clarity of a diamond.

When inspected through a 10 times magnification jewellers loupe the following grades are given

FL- Flawless; no inclusions and no blemishes

IF-   Internally Flawless; no inclusions

  • Very difficult for a trained grader to spot

VVS1-Very very slightly included grade1

VVS2-Very very slightly included grade 2

  • Difficult to spot and classed as minor

VS1- Very slightly included grade1

VS2- Very slightly included grade2

Inclusions are classed as noticeable

SI1- slightly included grade1

SI2- slightly included grade2

  • Inclusions classed as obvious and may affect transparency

I1- included grade1

I2- included grade2

I3- included grade3

COLOUR of your Diamond

The diamond colour evaluation of most gem-quality diamonds is based on the absence of colour. A chemically pure and structurally perfect diamond has no hue, and consequently, a higher value. D-to-Z diamond colour-grading system measures the degree of colorlessness by comparing a stone under controlled lighting and precise viewing conditions to master stones of established colour value.

The industry’s most widely accepted grading system is produced by GIA. The scale begins with the letter D, representing colourless, and continues, with increasing presence of colour, to the letter Z.

Many of these colour distinctions are so subtle that they are invisible to the untrained eye; however, these distinctions make a very big difference in diamond quality and price.

When an experienced pawnbroker such as Suttons and Robertsons assesses any piece of diamond jewellery for a diamond jewellery loan they will be assessing the above qualities to determine a loan value. As the 4 C’s of a diamond are assessed under laboratory conditions what has come more to the fore as an important part of assessing your diamonds value is a certificate.

Certificate-The fifth C

A diamond certificate is an evaluation by a third party. On it will clearly state the results as based on the 4 Cs. This evaluation will take the form of a laboratory certificate and must not be confused with an insurance valuation or the retailers stated opinion. There are several known grading laboratories eg

  • GIA- Gemological Institute of America
  • HRD- abbreviation of the Dutch “Hoge Raad voor Diamant”
  • IGI- International Gemological Institute

With these certificates you can contact a pawnbroker and they will be able to give you an estimate as to how much they would be able to give you as a pawnbroking loan.