Diamonds 4C's Ultimate Guide

The most important thing you should do before purchasing a diamond is to educate yourself about the factors that determine a diamond’s quality and price. To aid you, therefore, we have put together this guide to help you. It is the 4C's (Cut, Colour, Clarity, and Carat) that determine a diamond's lustre, sparkle, quality, and price, and your knowledge of them will enhance your shopping experience.


People often confuse Carat with Size, but they are not the same thing. In diamonds, size refers to the stone's measurement in millimetres, while carat is the weight of a diamond.

To help you understand the carat unit, we've provided an example. Take two diamonds that are both 1 ct. If the first one is cut very deep, it will look closer to a 0.80ct stone than an average 1ct one. If the second one is instead cut very shallow, the size of the diamond may look closer to a 1.25ct stone at the expense of its quality. As a result, a 1ct diamond that appears good will also weigh 1ct.

The quality of diamonds is always compromised when they are cut too deeply or too shallow. This results in them not reaching their full brilliance, and perhaps even looking lifeless or dark in the centre.


A diamond's “clearness” is determined by the Clarity grade; this grade determines how many and how few imperfections (called inclusions) the diamond has.
The Clarity grades, according to GIA, are as follows:

Flawless (FL), Internally Flawless (IF)

Diamonds with these grades have the best clarity. Flawless (FL) and Internally Flawless (IF) diamonds have no visible inclusions inside the stone when viewed through 10x magnification. However, unlike Flawless (FL) diamonds, Internally Flawless (IF) diamonds may have some surface marks (blemishes) under 10x magnification.

Very Very Slight Inclusions (VVS1 & VVS2)

It is followed by VVS1 and VVS2, which are the next highest clarity grades. Although a lower tier than FL and IL, the very tiny inclusions in VVS1 and VVS2 diamonds are incredibly difficult, even to gemmologists and diamond experts, to see under 10x magnification. Among the inclusions that may occur in a VVS diamond are pinpoints, needles, or internal graining.

Very Slight Inclusions (VS1 & VS2)

Even though they are lower grades than VVS1 and VVS2, VS1 and VS2 grades are still very eye-clean. VS1 and VS2 clarity diamonds have slightly larger inclusions than the VVS range. The inclusions are difficult to see in (VS1) but somewhat easier to spot in (VS2) if looked through 10x magnification. A diamond with VS inclusions may contain crystals, cavities, or clouds.

Slight Inclusions (SI1 & SI2)

Inclusions are more prominent in SI1 and SI2 clarity diamonds than they are in VS clarity diamonds. To the trained eye, these inclusions are noticeably visible under 10x magnification. Among the inclusions of SI diamonds are chips, knots, and feathers.

Included (I1, I2 & I3)

In terms of clarity, I1-I3 diamonds are the lowest grades. They have much more pronounced inclusions that are easily noticeable to the naked eye. Inclusions that are large, such as those found in an I clarity diamond, might interfere with the brilliance of the diamond.

A Recommendation from Novita:

We recommend getting the finest diamond you can afford based on the budget you have. We recommend you limit your choices to VS1, VS2 and SI1 diamonds and above to ensure the inclusions in the diamond are not visible to the naked eye, even when inspected closely.



Color is the most straightforward of all the 4Cs. A diamond's colour grade simply measures how colourless it is. The best diamonds are the ones without any colour in them, allowing their brilliance to shine through. The whiter or, to be precise, the clearer the stone is, the more valuable it becomes. As the colour grade lowers, tints of other colours, such as yellow or brown, start to be become noticeable, decreasing their overall value. The diamond colour grades by GIA goes from D (colourless) to Z (light yellow or brown). For simplicity, the grades are usually separated into tiers, since diamonds that differ only by 1 or 2 colour grades may appear very similar to the untrained eye.

D,E,F (colourless)
What are D-F grade diamonds? In addition to being the highest grade of colour, they are also the rarest. Being colourless, D and F diamonds are extremely clear and bright and have no yellow or brown tints whatsoever. D and F are grouped as colourless since when placed in a setting, they will both look the same, at least to an untrained eye. The difference between a D diamond and an F diamond can only be determined on a pure white background with both stones loose and side by side.

G,H (near colourless)
What are G-H grade diamonds? A close second to D and F, G-H are grouped together as near colourless and are the most popular. Although they have a very faint tint of Colour, in practice, it is not very noticeable at all to the naked eye. When in a setting, they will appear more or less white and still look colourless. Only when the loose stones are compared with colourless diamonds on a white background will the slight tint be noticeable.

I,J (very faint Colour)
What are I-J grade diamonds? This is the lower tier, and diamonds of this group are more common and of lower quality than the previous two tiers. They are classified as having a very faint colour. When compared to diamonds in the colourless or near colourless categories, I-J diamonds have a slightly more noticeable yellow, brown or grey tint. Any diamond with a colour less than J will have a significantly more obvious yellow, brown, or grey tint.

Recommended by NOVITA: Due to their clarity and colourlessness, D-F colour diamonds appear very similar to each other to the untrained eye, so there is no compelling reason to pick a D diamond over an E or F, save for personal choice. When the diamond's colour is at least F or higher, a greater portion of the budget can be allocated towards getting a better cut and shape.

Even though G-H colour diamonds are relatively affordable and plentiful, they are still very good choices due to their near colourlessness, making them an excellent choice for a “budget stone". Due to the substantial savings offered by G-H diamonds, you can purchase a much larger stone than you would be able to if you bought a D-F coloured diamond.
Recommended by NOVITA: You can save money or get a bigger stone when you go for diamonds D-G in Colour.


Finally, but perhaps most importantly, there is the Cut grade. It is impossible to overstate the importance of a good Cut, since it has the greatest influence on a diamond's appearance. The sparkle, fire, and brilliance that are all qualities associated with diamonds are all dependent on the Cut. If a diamond is not well proportioned, i.e. if it is cut too deep or too shallow, it will result in the light, which enters the stone, leaking out of the bottom of the diamond. Light entering a diamond should bounce back up and not leak out the bottom or the sides, thereby rendering the diamond dull and lifeless. Diamonds that are cut properly are brilliant in appearance. The light that enters a well-cut diamond reflects off all the sides, or the facets, of the diamond, come straight back up, imparting in the diamond a scintillating and otherworldly appearance. In fact, the diamond's cut can make a diamond of extremely high quality in each other category look dull and lifeless if its cut grade is not high enough.

Recommended by NOVITA: Never buy anything less than a diamond with an Ideal or Excellent Cut.

Novita Diamonds Guidance:

Our expert gemmologists have hand-picked each showroom option to ensure that you can view and purchase diamonds that are of the highest quality at your appointment and online. Our gemmologists sort through available diamonds and only choose the best diamonds in each colour and clarity category. Please visit one of our showrooms for further guidance on selecting the best stones for yourself or for loved ones.

You can filter diamonds on the Novita website using the 4Cs category, which is shown in the image below.

By clicking on the 'AVAILABLE IN SHOWROOM' tab and checking the 'SHOWROOM' column, you can further filter the available diamonds to show only the ones located in our showroom.


• Are lab grown diamonds real?

Without question, lab grown diamonds are genuine diamonds. They are produced using the same chemical and physical processes found in nature, but under controlled laboratory conditions, where a diamond crystal seed is gradually expanded with additional carbon atoms. From a scientific standpoint, lab grown diamonds are chemically, physically, and optically identical to mined diamonds, and are thus considered authentic diamonds. The leading diamond authorities, IGI and GIA, evaluate lab made diamonds according to the same scale and methodology used to grade mined diamonds, further confirming their legitimacy.

• How much cheaper are lab diamonds?

Lab grown diamonds are consistently more affordable than diamonds mined from the earth. The extent of the price difference is influenced by several factors such as the diamond's size, quality, and specific type, but on average, lab made diamonds in New Zealand can cost around 75% less than mined diamonds. This is due to the lower cost of producing rough lab grown diamonds compared to the expense of mining and extracting rough mined diamonds from the earth. However, both lab grown and mined diamonds must undergo the same processes, including cutting, polishing, and certification, to become retail-ready, regardless of their origin. For instance, you can save significantly by opting for a lab grown diamond over a mined diamond. A mined diamond may cost $10,000, while an equivalent lab grown diamond might only cost $2,500.

• Do lab diamonds test as diamonds?

Lab grown and mined diamonds are indistinguishable from each other. The same testing methods used to examine mined diamonds are also applied to lab grown diamonds. Both diamonds are chemically, physically, and optically identical, and display the same attributes and features when tested. These characteristics include hardness, refractive index, thermal conductivity, and other distinguishing characteristics of diamonds, regardless of whether they are mined or man made.

• Do lab grown diamonds have inclusions?

Inclusions can be found in both lab grown and mined diamonds. These are mined flaws that are typically present within diamonds. These imperfections come in various forms, including small bubbles or carbon deposits trapped inside the diamond during its formation. In the same way as mined diamonds, most lab grown diamonds have inclusions, and only a few become entirely flawless. For further details on diamond clarity, please refer to our 4Cs guide.

• Can I insure lab grown diamond rings?

Yes you can, it’s the same as insuring a mined diamond. You can obtain insurance for your lab grown diamond in NZ through almost any insurance as long as they insure jewellery. Typically, your insurance policy will cover the cost of replacing or repairing your ring in the event of loss, theft, or damage. It is important to read the terms of your insurance policy carefully to understand what is and is not covered.