Diamonds are graded and certified to global standards across four criteria, known as 'the Four Cs': cut, carat weight, colour and clarity.

Gradings, conducted by expert gemologists and recorded on a Diamond Certificate unique to each stone, directly determine a diamond's market value.

CUT covers a diamond’s proportions, symmetry and polish and is widely regarded as the most important of the Four Cs.

The cut is crucial because it governs the play of light within a diamond. A high-quality cut will maximize the amount of light reflected back through the top of the diamond, resulting in a stone with sparkle and fiery brilliance.

Even if the stone is graded higher in other areas, a poorly cut diamond will appear dull and lifeless: either not enough light has been allowed in, or too much has escaped through the sides.

As the quality of the cut plays such an important role in the visual allure of a diamond, the Australian Diamond Company selects its stones first and foremost for their superior cut.

CARAT is the worldwide weight standard for diamonds and gemstones. A carat is equal to 200mg and is expressed as a decimal. A full carat of diamond, for example, is written as 1.00ct and a half-carat is .50ct.

As carat refers to weight and not visual size, two diamonds of equal carat weight can appear quite different: one may be broader, but will be shallower as a consequence. For this reason, it is important to consider the carat weight in conjunction with the quality of the cut.

The other Cs, being the cut, clarity and colour of a stone will have a substantial influence on its value, so 'bigger' does not always equate with 'better'.

COLOUR refers to the purity and transparency of the stone, with each diamond graded from a totally colourless 'D' to a light yellow 'Z'.

A diamond's colour is an important indicator of its appeal, simply because even a faint yellowish hue will be visible to the naked eye.

We recommend stones graded D, E, F and G and advise our clients to avoid diamonds rated H or lower, where the yellowish tinge becomes noticeable.

G stones are generally regarded as good value, as their colour is almost undetectable to the untrained eye and providing the stone is well cut, will produce a dazzling performance.

In store, we’ll show you a range of stones with different colour gradings, allowing you to appreciate the difference and choose where you see value.

CLARITY measures the size, number and positioning of the natural blemishes or birthmarks, known as 'inclusions', within each stone.

Diamonds are formed within the earth over a long period, under extremes of heat and pressure, a chaotic process that leaves at least some trace of inclusion in almost every diamond on the market.

Clarity can have a significant impact on a diamond's value due to the obvious rarity of larger stones showing few inclusions.

The Clarity gradings are:

• Flawless (FL) and Internally Flawless (IF), indicating diamonds with no visible inclusions under 10x magnification

• Very, Very Slightly Included (VVS1 and VVS2) diamonds contain only minute inclusions that are extremely difficult to locate under 10x magnification

• Very Slightly Included (VS1 and VS2) diamonds contain minute inclusions that are relatively difficult to locate under 10x magnification

• Slightly Included (SI1 and SI2) diamonds contain noticeable inclusions under 10x magnification

• Included (I1, I2, I3) refers to stones with inclusions visible to the naked eye, which may also affect transparency and brilliance.

All Australian Diamond Company stones are 'eye clean' and graded SI1 and above, with no inclusions visible to the naked eye.

Some of our clients see value in the 'purity' of a stone, while others are looking for a balance between quality and value. Our consultants are happy to advise you on the clarity ranges that will best suit your goals and preferences.