Do the 4 C’s Really Matter? How to Buy a Diamond With Your Eyes

One of the first subjects you’ll come across when you begin your hunt for a diamond is the 4 C’s. There are hundreds of articles saying these are the most important factors when choosing a diamond. What are they? Color, Clarity Grade, Cut Grade, and Carat Weight. They make it easy and mathematical. If you buy an excellent cut 4 carat G color, VS2 clarity diamond, it will be beautiful, right? No!

The problem with boiling down a diamond to X Grades = Beautiful Diamond is that two diamonds with identical grades can look completely different. There is much more that goes into a diamond being attractive than just the 4 C’s, which is why you should always view them in person before purchasing. Here we will break down the 4 C’s and the other factors that contribute to a diamond’s quality.


The diamond color scale ranges from D through Z. You might be thinking, “I want a D because it’ll be the most white!” This is a great trick to get you to spend much more on a diamond than truly necessary. Diamonds D – F are considered colorless, and the difference is usually only noticeable to a trained gemologist. We recommend buying a G – I color diamond. Diamonds in this range are considered nearly colorless and give you the best value for your money.
Diamonds J and below get tricky. J color is when color begins to become easily detectable by the trained eye. But what color is it? Well, that depends! Diamonds can have a variety of undertones, including yellow, brown, green, and gray. Antique diamonds are often in the K-Z color range but are still very desirable.

Nine Cullinan diamonds on black background
The Cullinan diamonds are a great example of the beauty of antique diamonds

Before electricity and the invention of the modern Round Brilliant cut, the goal was different. Today diamonds are cut for maximum brilliance and minimal light leakage. Cutters of Old Mine and Old European cuts wanted to highlight the beauty of the diamond under warm yellow candlelight, so color wasn’t as important. Thus, these beauties sparkle magnificently in low light situations where you can’t tell the difference between a G and a J.


The GIA clarity scale includes Internally Flawless, Very Very Slightly Included, Very Slightly Included, Slight Included, and Included. Confusing, right? Clarity refers to the percentage of the stone that has inclusions, the types of inclusions, and where the inclusions are located.

Diamond Comparison
The difference between these 2 “identical” diamonds is clear

These two diamonds are both 2 Carat H SI1 XXX with no fluorescence graded by GIA. Yet, one is crisp, and the other is hazy due to internal graining and clouds. The hazy diamond was purchased from an online retailer.

We want to reframe how you judge clarity not by a diamond’s grade, but by the location of the inclusions and whether or not you can see them with your naked eye. For this reason, it is crucial to judge a diamond’s clarity in person, not online. It is difficult to determine what inclusions will be visible to the naked eye by its grade alone. Even an I1 diamond can appear mostly clean if the bulk of the inclusions are hidden under the crown angle facets.

Diamonds IF – VS2 will not have any inclusions visible to the naked eye, but you could end up paying double the price for an IF. If you ever intend to upgrade an IF stone, you also won’t get as much of your money back as you would on a VS2 due to a lack of demand.
SI diamonds are the most popular grades for a good reason. They are usually clean to the naked eye, and they have excellent resale value. Included (I1 and I2) will have noticeable inclusions to the naked eye, but how bothersome they are depends on the diamond. Some inclusions are white and difficult to see while others are black and stick out like flecks of pepper.


The most popular diamond cuts
Popular diamond shapes: round brilliant, cushion, radiant, princess, asscher, heart, trilliant, oval, pear, emerald, marquise, baguette.

The cut grade of a diamond refers to how well it is proportioned to maximize brightness, fire, and scintillation. Other factors also go into the cut grade, such as girdle thickness and the size and position of the culet. There is a mathematical precision that goes into crafting a well-cut diamond. A poorly cut diamond can be dull, leak light, or appear much smaller or larger than its weight.

Cut grade is significant when it comes to choosing a modern diamond. It’s complicated to understand unless you can compare a selection of stones side by side. However, it’s not nearly as relevant to antique diamonds. By today’s standards, antique diamonds are all terrible cuts! GIA does not give cut grades to antique cuts for this reason. Not one antique diamond is the same, which makes them unique and interesting.


You may have heard that fluorescence is a bad thing because it makes the stone appear cloudy. This is only true for a small percentage of diamonds. Fluorescence often does not affect the appearance of the stone or can even make it look whiter than it is. However, it does affect resale value. So while you might get a discount by purchasing a fluorescent diamond, they do not trade as well on the second-hand market because of the perception that fluorescence is always bad.

The Bottom Line

Purchasing a diamond online from a company like Blue Nile may be easy, but it is always best to view several diamonds in person so that you can compare them. No two diamonds are completely identical. We recommend taking the 4 C’s with a grain of salt. Decide the size, shape, and price you’d like to stick to and go from there.

At Austin Jewelry & Diamond Buyers, we believe beauty really is in the eye of the beholder. With our private bridal service, we show you a selection of diamonds so that you can decide for yourself which diamond is your favorite. All of our diamonds are GIA certified unless specified otherwise. No tricks, no hassle, just beautiful diamonds selected with our critical, trained eye.

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