Precious Advisory

Ethical Sourcing

Precious Advisory

After more than 10 years working in diamond industry in Europe. I’ve travelled to Thailand and understood and knew very quickly that Bangkok is a Major City for Diamond Trading.

The 4 C’s of Diamonds

Cut  Color  Clarity  Carat

When buying a diamond, it is important to know about the 4 C’s. Together, the 4 C’s: Cut, Color, Clarity, and Carat Weight determine a diamond’s value.


When discussing a diamond’s “cut,” we take into account not only its shape but also the quality of the cut itself, which can be assessed based on factors like proportion, texture, and symmetry. Ultimately, a diamond’s beauty largely depends on this aspect of its makeup.

Primary Factors in Setting a Diamond’s Value
  • Proportions: table, width, and depth
  • Symmetry
  • Brilliance
  • Fire
  • Scintillation
  • Finishing/Polish

The cut of a diamond also plays a role in determining its value. For example, Triple Excellent Cut diamonds command a higher price than those graded as Very Good, Good, Fair, or Poor. When it comes to round diamonds, those classified as Excellent or Ideal Cut have the most perfectly proportioned facets. Additionally, if a diamond displays “Hearts & Arrows” patterning, it will be even more beautiful because H&A diamonds require meticulous craftsmanship and take more time to cut than standard faceted diamonds.


Diamonds can exhibit various hues such as blue, pink, or yellow. However, the most common choice for an engagement ring is a white diamond, as it is considered a symbol of purity due to its colorless appearance.

The GIA Institute has developed a widely accepted color grading system for white diamonds, which ranges from D (colorless) to Z (yellowish). For diamonds in the fancy color range, such as blue, pink, or yellow, a different set of criteria is applied to determine the diamond’s color.


  • D, E, F: Diamonds of colourless grade are considered as purest and rarest of all. They have a high demand in the market and command a good value. Further, they can be paired with almost every metal.
  • G, H, I, J: This set of nearly colourless diamonds consists of a slight tint that is often imperceptible by a naked eye.
  • K, L, M: This set of faint yellow-coloured diamonds consists of a perceptible yellow tint.
  • N, O, P, Q, R: The most inexpensive diamonds of all, this set of very light yellow diamonds has a light yellow or a brown tint inside them. Moreover, they have a very low demand.
  • S, T, U, V, W, X, Y, and Z: This set of light yellow coloured diamonds consists of a yellow hue and thus does not fit for a “white diamond”.

The color of a diamond can significantly impact its price, with a D-color diamond being the most sought-after by purists due to its lack of yellow tint. Therefore, D-color diamonds typically hold a higher value compared to diamonds with a yellow tint.

Precious Advisory adheres to the GIA international standard for color grading, which ensures that each diamond’s color is accurately measured in the correct lighting environment to eliminate any chromatic aberration. This ensures that the diamonds we deliver to you are of the highest quality.

3. Clarity

Clarity is an important factor in determining the quality of a diamond. It refers to the presence or absence of inclusions and blemishes on the diamond’s surface or within the diamond itself. Similar to a birthmark on a newborn’s body, these defects are unique to each diamond.

The smallest amount of blemishes or inclusions is what defines diamond clarity. The location of the defect also determines its visibility. For example, defects on the front of the diamond are more noticeable than those on the outer edges. Additionally, if the diamond has too many inclusions, it can hinder the light passing through the diamond and affect its sparkle.

Diamond clarity is the second most important factor in determining the value of a diamond after carat weight. The cleaner the diamond is, the higher its price. For example, diamonds with the IF clarity level (internally flawless) will always command a higher price. Diamonds that fall below the SI clarity level (slightly included) may have visible defects to the naked eye and therefore, are sold at discounted prices.

FL- Flawless Extremely rare and valuable among all diamonds. Very few diamonds have the diamond clarity of FL.
IF- Internally Flawless Less than 3% of all diamonds have a clarity of IF.
VVS1-VVS2- Very Very Slightly Included (1 and 2) Slightly included diamonds either on the pavilion or on the crown.
VS1-VS2- Very Slightly Included (1 and 2)> Inclusions are invisible to the naked eye. However, on close inspection, one can see the inclusions.
SI1-SI2- Slightly Included The diamonds with this clarity can reveal inclusions on close inspection.
I1, I2, I3- Included (1,2 and 3) This set includes diamonds that are heavily included and often more prone to breakage.

It is important to note that more than one-third of diamonds sold worldwide have undergone lab-based “wound healing” processes, which involve using a laser and acid to make the flaw appear smaller and improve the diamond’s clarity. However, this process decreases the value of the diamond. Thus, we do not sell diamonds that have undergone such processes.


A diamond’s weight is measured in carats, with 1 carat diamond equivalent to 0.2 grams and 100 points. If a diamond weighs less than one carat, such as 0.30 carats, it is commonly referred to as a “30 pointer.”

Among the 4Cs, carat weight is the only factor that can be technically measured, and special precision scales are used to obtain the diamond’s exact weight.

However, it’s important to note that comparing diamonds based on carat weight alone is similar to comparing the value of a work of art based on size. A large painting by an unskilled artist cannot be compared to a small painting by Picasso. Therefore, diamonds of the same carat weight but different sizes will have the same points but varying prices. The overall value of a diamond depends on the other factors within the 4Cs.

In general, larger and heavier diamonds are rarer and more expensive. The price of diamonds increases at each “staging post” in carat weight, but not in a directly proportional manner. Choosing the right carat weight is a matter of personal preference and budget.

Precious Advisory offers the option to select diamonds directly from some of the world’s largest diamond cutters through our website, making it easier for you to find the perfect size for your needs.

Precious Advisory takes pride in being not just a source for your jewelry, but also a place where you can freely discuss your current and future requirements. Our commitment is to provide you with meticulous and detailed information, to ensure that you get the best possible advice while selecting your diamonds.
By having a basic understanding of how to view a diamond’s certificate, you can make more informed decisions when purchasing diamonds that align with your preferences and budget.

Contact Us

    Select the fields to be shown. Others will be hidden. Drag and drop to rearrange the order.
    • Image
    • SKU
    • Rating
    • Price
    • Stock
    • Availability
    • Add to cart
    • Description
    • Content
    • Weight
    • Dimensions
    • Additional information
    Click outside to hide the comparison bar