Diamond Information

The existence and visual appearance of internal characteristics of a diamond


Diamond colour is all about what you can’t see. Diamonds are valued by how closely they approach the colourlessness


Cut quality is the factor that fuels a diamond’s fire, sparkle and brilliance. The allure and beauty of a particular diamond depends more on cut quality than anything else


Refers to the outline of the stone (round, oval, princess etc)


The unit which a diamond is measured by


Diamond Cut


A shallow cut diamond has the light escaping from the bottom.


If the cut of a diamond is perfect, light will strike each pavilion facet and reflect upwards to the crown mostly.


Light escapes or refracts from the bottom or the side of a deep cut diamond.

Cut is an important characteristic to look for when searching a diamond, this determines the amount of sparkle given. The rule to brilliance and beauty within a diamond is to reflect their true characteristic which is expressed through the cut. Further, the value of a diamond is determined by how well the facets interact with the light. A diamond cut does not refer to the shape but also to its proportions, symmetry and polish. The size, shape and angle of each facet of a diamond is characterised as a diamond proportion. When a diamond cut with proper proportions, light is returned out of the top of the diamond. If it is cut too shallow, light leaks out of the bottom, too deep and it escapes out of the side.

There are three proportional factors that determine a diamonds cut quality, and these include:

  • Brightness: internal and external white light reflecting on a diamond, which is the combination of light reflecting from the surface and inside the diamond.
  • Fire: white light reflecting into all colours of the rainbow, flashes of colour within the diamond.
  • Scintillation: amount of sparkle produced by a diamond, the deeper the cut the more sparkle or shine flashes of light and dark or sparkle when moving the diamond around (Ziba and Co recommends an ideal cut).

Additionally, in the diagram below, three common light patterns are shown which affect the diamond’s brilliance, the most important of which is its ability to reflect light. As a diamond passes through a light source, tiny flashes will be visible within the stone.

How diamonds are Measured

The depth of a diamond can be determined when viewing a diamond from the side; it is the distance between the culet and the table. This is usually measured in millimetres (the third number of measurements). The depth of a diamond is calculated by dividing the depth with the width. The table of a diamond is calculated by the width of the table by the width of a diamond.

Note: When diamonds are cut they already incorporate both the depth and table. This cut should be the first element to look for when searching for the right diamond. If diamonds are equal in cut, then the depth and table can be used to refine the selection.

Diamond Cut Grading

Polish and symmetry are the two important aspects of a diamonds cut. The smoothness of diamonds facets are determined by its polish and the alignment of facets are established by the symmetry. The size, shape and angle of each facet of a diamond is characterised as a diamond proportion. When having a poor polish, the diamond appears to be dull; this may create a blurred or dull sparkle. A diamond with a poor polish often has a grain of lines running along the facets. This may make the diamond appear as if it needs constant cleaning. With a poor symmetry, it can often mislead a diamond as the light being entered escapes from the diamond.

ExcellentExceptional fire and brilliance. All light entering the diamond creates an extraordinary sparkle and shine.
Very GoodReflects light properly that is being entered in the diamond. This cut appears to be similar to an Excellent cut, with a very high brilliance for a lower value.
GoodReflects majority of the light that enters the diamond, for a moderate appearance. It is at excellent value in comparison to a higher cut grade.
FairThe light that enters the diamond escapes from the sides or bottom, this leads to less fire and brilliance. The light is lost and it noticeably less luminous.
PoorAllows the light that enters the diamond escapes from the sides or bottom. The diamond appears to be lifeless and dull.

Expert Buying Tips

  • Diamonds with a cut grade of good or very good represent an excellent combination of beauty and value.
  • For greater brilliance, choose a diamond with a Cut grade of Very Good or Excellent for round diamonds, and Good or better in fancy shape diamonds.
  • For those on a budget, primarily concerned with size, a diamond of Fair – Good cut may be an acceptable choice, especially in fancy shapes.

Have A Question?

Contact us by email at info@zibaandco.com.au. In addition, Live Chat is available during most business hours.

Diamond Colour

The colour within a diamond is determined by how much or how little colour is a diamond has. The colour is generally regarded as the second most significant characteristic of a diamond. In order to have a brilliant white diamond with sparkle, colour is the aspect that should be focused on as it can be visible to the naked eye. The Colour in a diamond ranges from completely colourless high in value (D Colour Grade) to low in value light colour grade (S-Z Colour Grade).

Diamond colour grade chart

Expert Buying Tips

  • For the traditionalist, look for a colourless grade of D-F for a diamond with no visible colour under magnification.
  • Looking for the best value, choose a near-colourless grade of G-J for a diamond with no visible colour by the naked eye.
  • Diamonds with more facets mirror more light, they tend to conceal colour better than other shapes.

Have A Question?

Contact us by phone at 0410 466 770 or by email at info@zibaandco.com.au. In addition, Live Chat is available during most business hours.

Diamond Clarity

The clarity of a diamond is the third most important aspect to look for when choosing a diamond, imperfections within a diamond can only be seen under professional magnification.

The Clarity of a diamond refers to the little imperfections which are known as inclusions. These numerous or significant inclusions in a diamond are tiny external and internal blemishes that determine the grade point. Inclusions and blemishes are shown throughout all diamonds; these are little birthmarks for each stone which have less brilliance because the flaws interfere with the path of light through the diamond. It is very rare to find diamonds that have no inclusions or blemishes at all as it affects the diamonds value.

Diamond size does determine how noticeable the inclusions and blemishes are within the diamond, the larger the stone the more visible it becomes. Depending on the clarity each diamond has determines whether or not it can be visible to the unaided eye.

To ensure a great selection, Ziba and Co offers diamonds with a range of clarity rating from Flawless to I3. Diamonds with clarity rating of I1 or higher hold inclusions and blemishes that are unnoticeable without particular magnifies viewers.

A diamond’s clarity rating is based on the number, size, and location of internal or external uniqueness. Internal uniqueness includes crystals, clouds and feathers. While external are called blemishes. These inclusions however can’t be seen by the naked eye.

Expert Buying Tips

  • The well-liked variety is the VS1-VS2 diamond. These diamonds appear flawless to the naked eye, and are a part of the price of a truly perfect diamond.
  • The next well-liked variety is SI1, where the inclusions are usually not important to impact the look and appearance of the diamond for people.
  • The bigger the diamond, the easier imperfections are to discover; thus clarity becomes more significant.

Have A Question?

Contact us by phone at 0410 466 770 or by email at info@zibaandco.com.au. In addition, Live Chat is available during most business hours.

Diamond Carat

The carat weight is the most important aspect in the diamonds 4cs as it is the most well-known and misunderstood. A diamond’s cut impacts how large the carat weight will appear as the smaller carat weight diamonds will appear larger with higher cut grades.

The size of a diamond is determined by its weight. The weight is expressed in metric carats; one carat is equal to 0.2 grams.  The word carat is often abbreviated as “CT”. If a diamond weighs less than one carat then it is expressed as points (0.75pts). Once a diamond becomes larger than one carat it is then indicated as carats and decimals (1.05CT), this then becomes one carat and five points. Diamond prices increase with carat weight as larger diamonds are less common and become more desirable. However, two diamonds of equal carat weight can have dramatically different values depending on its colour, clarity and cut.

Expert Buying Tips

  • The smaller carat weight diamond may have a diameter equal to that of a heavier diamond, making it appear that same carat size when viewed from above.
  • Diamond values rise at the full- and half-carat weights. Diamonds just under these weights cost significantly less, and, because carat weight is distributed across the whole of the diamond, small size differences are almost undetectable.
  • The smaller the figure, the larger the diamond will appear.

Have A Question?

Contact us by phone at 0410 466 770 or by email at info@zibaandco.com.au. In addition, Live Chat is available during most business hours.

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