an image of a diamond labeled in its parts

The 4Cs: Choosing a Diamond for an Engagement Ring

an image of a diamond labeled in its parts

Making the decision to propose to your partner is a momentous occasion and something to celebrate. It is also quickly followed by another big decision: Choosing the right engagement ring!

Picking the perfect ring for your partner will largely depend on their personal style and tastes—but if you’re opting for a “traditional” engagement ring, it’s important to consider the quality of the diamond center stone. Diamonds are available in a variety of sizes and shapes, but are all ultimately graded on four factors, known as the 4Cs: cut, color, clarity, and carat. Each factor plays a distinct role in the overall beauty and value of the diamond. Let’s dive in.


We often think of a diamond’s cut as shape (round, emerald, pear), but a diamond’s cut grade is really about how well a diamond’s facets interact with light. A well-cut diamond will sparkle and reflect light beautifully, and the quality of cut is crucial to the diamond’s final beauty and value. Of all the 4Cs, a diamond’s cut is the most complex and technically difficult to analyze.

The GIA Cut Grading System for the standard round brilliant diamond evaluates seven components. The first three, brightness, fire, and scintillation, consider the diamond’s overall face-up appearance. The remaining four, weight ratio, durability, polish, and symmetry, assess a diamond’s design and craftsmanship.

Important to note: Cut is not the same as shape! Shape refers to the outline of the stone, while cut refers to a stone’s facet arrangement. The most common diamond shape used in jewelry is round, while all other diamond shapes (like pear or marquise) are known as fancy shapes.


Interestingly, the color evaluation of most gem-quality diamonds is based on the absence of color. A chemically pure and structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value. GIA’s D-to-Z color-grading scale is the industry’s most widely accepted grading system, and assigns a grade based on a scale from D (colorless) to Z (light yellow or brown). That being said, some people prefer diamonds with a hint of color, and a hued diamond can still be beautiful and striking.


Natural diamonds are formed under intense heat and pressure deep within the earth—a process which can result in a variety of internal characteristics called “inclusions” and external characteristics called “blemishes.” Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone.

While no diamond is perfectly pure, a higher clarity typically results in a higher value. Because “flawless” stones are extremely rare and expensive, most people choose diamonds with a few blemishes that are not visible to the naked eye—but some people love the unique look of “salt and pepper” diamonds that have many visible inclusions.


One of the most commonly discussed features of diamonds is its carat weight, a measurement of how much a diamond weighs. A metric “carat”is defined as 200 milligrams; each carat can be subdivided into 100 “points,” which allows for very precise measurements to the hundredth decimal place.

All else being equal, diamond price increases with carat weight, because larger diamonds are rarer and more desirable. But two diamonds of equal carat weight can have very different values (and prices) depending on the clarity, cut and color. It’s important to remember that a diamond’s value is determined using all of the 4Cs, not just carat weight.

Keeping the 4Cs in mind can help you find the perfect diamond for your proposal—but most importantly, you should consider the style and preferences of your partner. We can help you find the perfect diamond for your budget and preferences.

Getting started on your diamond-buying journey? We’re here to help!

Schedule an appointment to visit our showroom today.