The main four factors are known as the four Cs: Cut, Color, Clarity, and Carat. In this article, we will go over what each of these mean and how it helps us determine the rarity and price of a diamond. We will also dive into how you can optimize these factors to get the best stone out of your budget.

Carat is a measurement of mass: a single carat weighs one fifth of a gram. Diamonds are priced per carat, and the price of a diamond rises exponentially as carat weight increases. Many people confuse carat to be a determinant of size rather than weight. However, it is possible for a 1.9 carat diamond to look larger than a 2 carat stone because of differences in proportions and angles. Since prices rise exponentially with carat weight thresholds, you can sometimes find a smaller stone that seems larger without crossing the threshold. This is a savvy way to save a great deal of money. 

Diamonds come in all colors, but the most common and desired diamond color is actually no color. Colorless diamonds are commonly referred to as white diamonds and are graded on an alphabetic letter scale ranging from D (completely absent of color) to Z (lightly tinted, usually yellow). Small differences in color grades can be tied to large differences in price and are usually only detectable by the trained eye. For the untrained eye, it is easier to split this grading from D to Z into five categories: Colorless (D-F), Near Colorless (G-J), Faintly Tinted (K-M), Very Lightly Tinted (N-R), and Lightly Tinted (S-Z). The average person cannot distinguish between color grades but could distinguish between the color categories explained above, so savings could be achieved by going for a lower color grade within the color category you desire. 

To the untrained eye, clarity can be a very tricky determinant of quality and rarity. Diamond dealers inspect the goods they buy and sell with a simple small lens that magnifies their vision ten fold, this tool is called a jeweler's loupe within the trade. This allows them to inspect the clarity of the diamond by looking for impurities, also known as inclusions. The less impurities or the less obvious they are, the higher the clarity grade assigned to the stone becomes. Just like color, clarity is described using a sliding scale, but not an alphabetical one. Clarity grades range from Flawless to Included and are each assigned an abbreviation:

• FL: Flawless diamonds have no impurities within them visible with a jeweler's loupe and are also absent of any surface blemishes. 
• IF: Internally Flawless diamonds are absent of any impurities within visible with a 10x loupe, however, they may still have some slight blemishes on the surface such as polishing lines (a remain of the manufacturing process). 
• VVS1/ VVS2: Very, very slightly included diamonds have impurities that are difficultly visible to a trained eye inspecting the stone with a jeweler's loupe. These impurities are not visible to the naked eye and are usually not visible to the untrained eye even when using a loupe. The VVS category is split into VVS1 and VVS2: in VVS1 stones the impurities are harder to find than in VVS2 stones. 
• VS1/ VS2: Very Slightly Included diamonds have minor impurities that can be spotted by a trained eye using a 10x loupe. These impurities are observable with effort, but they usually do not impair the stone visually.
• SI1/ SI2: Slightly Included diamonds have impurities that are easily spotted with a trained eye using a 10x loupe. The inclusions are usually prominently positioned in the stone and can sometimes be observed from the naked eye. 
• I1/ I2/ I3: Included diamonds have impurities that are immediately visible using a 10x loupe. The inclusions are prominently positioned in the stone, impair the stone visually, and are usually visible to the naked eye. 

In our many years of experience, we have seen SI1 and SI2 stones that look visually more appealing than a VS2 due to a more fortunate placement or type of inclusions. Understanding the inclusion types also helps you decide for the best stone your budget can get. The most common inclusions are pintpoints, crystals, clouds (which are groups of crystals and/or pinpoints), and feathers. Pinpoints and crystals can be transparent or black; stones with black inclusions are usually cheaper than those with transparent impurities. In the end, what matters most is that the diamond is visually appealing to you and you don't feel disturbed by the inclusions present within. 

Cut is the most misunderstood factor determining a diamond's value. Most people immediately think of the different shapes that diamonds come in, however, this is not what is meant by the cut grade. Cut actually consists of three separate elements: a cut grade, a symmetry grade, and a polish grade. These grades range from poor, fair, good, very good, to excellent. The cut grade only applies to round brilliant diamonds: since the round brilliant shape is designed to maximize the brilliance of the stone, there are strict parameters of angles and proportions that must be respected. Since every facet of a diamond acts like a mirror, having good symmetry is crucial to the optics of the stone. Stones can look boring and dull when the facets are not symmetrical. The polish grade refers to the quality of the surface of a diamond. Diamonds are polished on polishing wheels lined with diamond dust; when the polisher does not finish the diamond properly, there could be polishing lines left on the surface that affect the brilliance of the diamond ever so slightly. 

Now that we've covered the four Cs, there is one more factor mentioned on every certificate, but rarely talked about: fluorescence. Some diamonds can emit visible light when exposed to a black light. This light is graded based on its intensity from none, faint, medium, strong, and very strong fluorescence. Exposing your diamond to a black light could make it emit a soft blue, yellow, white, orange, green, or pink glow. Traditionally, stones without fluorescence are preferred by the market. In some stones, fluorescence makes them appear hazy, and thus less desirable. In other cases, the stone can actually seem whiter than its grade due to the fluorescence present in the material. Fluorescent stones are usually priced lower than their non-fluorescent equivalents. However, some people see a strong fluorescence as a nice hidden feature of their diamond that can appreciated by its owner or wearer. 

These factors are used to judge all diamonds, however, there is a category of diamonds that we did not discuss in this article. Diamonds come in all colors, and not all colors are equally rare or desirable. To learn more about these treasures from nature, click on Fancy Colored Diamonds under the education section on our website. 

Should you require additional information please do no hesitate to book a non complimentary a 30 minute consultation with one of our colleges.