Diamond Buying Guide

A Diamond is a crystal that is highly sought after its beauty and hardness. Choosing a diamond is a very valuable investment and can provide as the perfect stone for an engagement ring or adorned in necklaces, bracelets and earrings. Choosing the right diamond not only for the occasion but for its quality is a different matter altogether. The buyer must be aware that no two diamonds are the same even if they are cut from the same rough stone. This quick guide aims to inform the consumer as to how to determine the quality of diamond they are purchasing.

There are four main C’s that represent the characteristics of a diamond. These are Cut, Clarity, Color and Carat Weight.


This is probably the hardest to determine as most consumers confuse the cut of a diamond with its shape. Shape refers to the general appearance of a diamond and is classified as Asscher, Cushion, Round, Emerald, Heart, Oval, Princess, Radiant, Round Brilliant or Pear. Cut refers to the diamond’s reflective qualities.  The consumer can identify the quality of the cut of the diamond by examining how the light travels through the stone. If the light enters from the top and upon hitting the pavilion travels to the other side and then reflecting back to the top then the diamond is considered an ideal cut. This movement of light is what gives the diamond its sparkle. A poorly cut diamond would mean that the light would leak out of the sides and this would result in a lack of shimmer to the eyes of the consumer. Cut is classified as: Ideal, Premium, Very Good, Good, Fair & Poor.  It has to be noted that the Ideal cuts correspond to round diamonds and are small in carat weight. This is due to the excessive cutting of the rough diamond in order to get that perfect cut.  Generally speaking, the larger the diamond the more these diamonds are cut outside of the ideal proportions. This means that these diamonds are larger with heavier carat weight. This also means that the diamonds ability to handle light and create brilliance is substandard compared to diamonds cut in ideal proportions.


Clarity would indicate the presence of two flaws:  Blemishes and Inclusions. Blemishes are found on the stone while inclusions are found within.  Blemish flaws are characterized as scratches, pits and chips. Inclusion flaws are characterized as air bubbles, cracks, and non-diamond minerals found within the diamond.  To check the flaws of a diamond, the consumer should use a 10x loupe and scan the diamond. Flaws are graded under the following:  F- Flawless, IF-Internally Flawless (Surface flaws present), VVS1-VVS2-Very Very Slightly Included seen under 10x loupe, VS1-VS2-Minute Inclusions seen under 10x loupe, SI1-SI2-Slightly included seen under 10x loupe, I1-I2-I3-Included seen under both 10x loupe and naked eye. If buying a diamond for an investment the consumer should be aware that the clarity of the diamond plays a significant role. The more flawed the diamond the lower the value of the diamond. 


Color in diamonds and in particular to white diamonds refers to the colorless attribute of the diamond. A colorless diamond allows the diamond to exude the maximum effect of its brilliance and due to the rarity of colorless diamonds they are in fact of great value. This is not to say that only colorless diamonds are great value. There are also fancy color diamonds that that range from blue to yellow and that are highly valued for their color. The characteristic of color is more flexible due to the aesthetic preferences of the consumer. Like other characteristics there is a grading when selecting a white colorless diamond. These are:  D /E/F – colorless, G/H/I /J– near colorless, K/L/M – faint yellow, N/O/P/Q/R – very light yellow, S/T/U/V/W/X – light yellow. Diamonds graded from D to F are generally the most valuable as far as white colorless diamonds goes and grades G to I are acceptable while grades J onwards display traces of color. Although the nature of color is more related to aesthetics and as such the colorless or presence of color is dependent on the consumer’s preference.

Carat Weight:

Carat weight refers to the weight of the diamond. One carat is equivalent to 0.2 grams. The consumer should be aware that a carat weight is different from karat. Karat is used to determine the purity of gold and not related to selecting the perfect diamond. A carat weight only directly affects the value of a diamond due to its weight. Although indirectly a carat weight may affect the quality of a diamond as well, this has to be taken into consideration with other characteristics as well. As mentioned earlier, the highly valued ideal cut diamond may reflect more light and is thus smaller. This would mean a lower carat weight although a larger carat weight may be purchased but the quality of the cut would be lower correspondingly.

These are the four main characteristics of choosing a diamond. However they are not the only factors that should be considered. Another key factor before purchasing a diamond is the jewelry store that the consumer goes to.

The following are key characteristics of a good jewelry store.

  • Credentials of Store – Is the store affiliated with any organization?
  • Knowledge of Salespeople – Now that you the consumer have some knowledge about selecting a diamond, do they share the same knowledge or are they unable to answer your questions? If it is the latter then it is best you avoid this shop.
  • Use of a loupe – If you brought a loupe do they allow you to inspect the diamond? If you did not bring a loupe do they have a loupe for you to inspect the diamond? If they won’t allow to you inspect the diamond and they don’t have a loupe then you should avoid this shop.
  • Variety – Do they have a lot of variety of gems? Is there a large variety of quality as well? If the answer is yes then it is a good shop. If the answer is no and if you notice a large collection of bargain priced diamonds then it might be a good idea to look elsewhere.
  • Services – Do they provide cleaning and mounting services? What about jewelry customization? Generally speaking high quality diamonds are un-mounted which allows the consumer to inspect them thoroughly. Also check their policies on guaranties. If you are spending a lot of money on a high quality diamond then you would want some sort of guarantee, and if the store is selling a high quality diamond they would give you that guarantee. Make sure to read the guidelines of guarantees and return policy.
  • Does the store provide you with documentation of the diamond in question? Is the diamond lab tested? If it is do they allow you to contact the lab in order to confirm its quality? If not, do they give you a documentation of the diamond and send the diamond to be tested? If they say no to all of these then leave the store. There should be no problems in sending a diamond to be tested.

Before the consumer would go forward in purchasing their diamond, they should be familiar with all the characteristics mentioned above. The consumer should also prepare a budget that they are willing to spend and they should know as to the size and design of the jewelry if the consumer plans to set the diamond.