Your Guide To Choosing The Perfect Diamond


Are engagement bells ringing in your future? Let's take a deep breath and read up on what makes a quality diamond.

Here at Plum Diamonds, we're your one-stop shop for classic, gorgeous diamond cuts, and we're ready to take you by the hand and explain the 4Cs of understanding diamond quality.

Grab yourself a glass of something celebratory and dive into this beautiful, sparkly world with us!

What are the 4Cs of Diamond Quality?

In the wild west of jewelry, there was no standard way to evaluate diamonds. Diamond traders and jewelers would use words like "well" or "poorly" to describe cuts, not an exact science for something that is one of the biggest purchases you can make.

Thankfully, in the 1940s, the founder of the Gemological Institute of America (GIA, to you and me) created the revolutionary concept of looking at the following 4Cs to understand diamond quality with an accessible, universal framework:

- Color

- Clarity

- Cut

- Carat Weight

GIA Lab Diamond Report

Why Do the 4Cs Matter?

We'll get into exactly how you can use the 4Cs to purchase the diamond engagement ring of your dreams in a moment. In the meantime, here's why they matter. 

Nowadays, the 4Cs is the universal method for assessing  the quality of any diamond, no matter where you are in the world. This type of grading is trusted by world-famous museums, elite auction houses, and shoppers everywhere to assess these sparkling treasures.

However, keep in mind that a diamond graded perfectly in all areas will likely cost a considerable fortune, and there is no “correct” set of diamond specifications. It's all about weighing up which areas are most important to you. See the 4Cs as a guide rather than a strict rulebook.

Understanding Diamond Color

Fun fact: when we discuss grading color in a diamond, we're grading based on a complete lack of color. The grader will pick up the diamond and place it UPSIDE DOWN next to the individual diamond in their master set to compare colors. Do you see how grading is both an art and a science?

The scale runs from D (the best color, which is actually lack of color) to Z (a light yellow hue). We recommend prioritizing color over clarity in most cases, because you're more likely to see color than clarity characteristics with the naked eye. 

While D-F is considered colorless, the cream of the crop, you must remember that diamond color comes down to personal preference and does not necessarily dictate the quality of the diamond. 

Understanding Diamond Clarity

Diamond clarity refers to a lack of inclusions or blemishes within or on the surface of the diamond. Diamonds are created when carbon is exposed to extreme heat and pressure or through chemical vapor deposition. Other minerals and elements are often introduced in the growth process, both in nature and in lab created diamonds. That growth process is when inclusions and external blemishes can occur.

The diamond formation process is more controlled in a lab; however, like mined diamonds, most lab diamonds are not completely flawless and have their own unique “fingerprints” or inclusions.

There are six grades for diamond clarity; here’s an overview, or you can do a deep dive of Diamond Clarity Charts:

- Flawless (FL)

- Internally Flawless (IF): when magnified at 10x, no inclusions are visible.

- Very, Very Slightly Included (VVS1 and VVS2): inclusions so tiny they are challenging for the grader to see under 10x magnification.

- Very Slightly Included (VS1 and VS2): inclusions are observed with effort under 10x magnification but are minor.

- Slightly Included (SI1 and SI2): inclusions are perceptible under 10x magnification.

- Included (I1, I2, and I3): Inclusions are noticeable under 10x magnification which can affect brilliance and transparency.

If you’re looking for an eye-clean diamond, VS2 and up is considered the “safe” zone of diamond clarity. But if you're looking for an extra great value, don't automatically reject the SI range. Plum offers SI1 because there can be excellent value in this range for brilliant cut diamonds (round, oval, cushion, radiant, and pear).

IGI Lab Diamond Report

Understanding Diamond Cut

Diamond cut is not the same as a diamond's shape. Shape is simply what it sounds like, while many consider cut to be the most important of the 4Cs. It's also the only 4C humans can directly influence.

Diamond cut is all about how well a diamond is cut and polished. In a nutshell, a poorly cut diamond can lose points on aesthetic appeal and value as it won't reflect light correctly, causing it to appear dull rather than brilliant.

For this reason, we agree that cut is extremely important and only offer the highest cut grades whenever possible.

Keep in mind, an official diamond cut grade issued by the GIA only applies to round diamonds. You might sometimes see cut grades listed next to non-round (“fancy”) shaped diamonds, but this is typically just the diamond cutter’s opinion.

The GIA cut grade scale is specifically assessing round diamonds. Here’s what you can expect from each grade, or jump over to our Diamond Cuts page to learn all about Different Diamond Cuts and Shapes:

- Excellent: the highest level of brilliance and sparkle

- Very Good: exceptional brilliance, similar to perfect to the naked eye

- Good: showcase some brilliance and sparkle, good price point

- Fair: very little brilliance, still a good choice for smaller carats and side stones

- Poor: no sparkle or brilliance, light escapes from the sides and to the bottom

Understanding Diamond Carat Weight

You often hear celebrity engagement rings being touted based on the size of their carats. After all, a high-carat ring can be quite the status symbol.

Carat is the measurement we use in the diamond industry to describe the physical weight of diamonds. If you're into the math of it all, one carat is 0.200 grams.

You must remember that weight is not the be all and end all of diamond quality. Since larger diamonds tend to be rarer than smaller ones, they are often higher priced, but color, clarity, and cut also have to be considered when grading diamonds.

A couple of tips to keep in mind regarding diamond carat weight:

- Think of carat weight like body weight. Imagine two people who each weigh 150lbs. They might look very different and carry their weight in different ways. That’s why it’s important to remember that a bigger carat weight isn’t everything. Be wary of low cost/high carat diamonds, as they may not be proportioned well. And of course look out for cut grade to make sure the diamond is properly cut for brilliance.

- Not everyone wants a huge diamond! For example, we find that 3cts feels too big for many women. Don’t fret if that 5ct is out of reach or seems like too much to you. You’re not alone!

3 Diamond Rings On Display

About: Plum Diamonds

Do you feel like you know the ins and outs of how to pick a quality diamond now? Mission accomplished!

Remember, you can always get advice when trying to make a crucial diamond-related choice. We don't expect you to become an expert right off the bat. That's why we have years of industry experience to back us up! Let us help you find the ring of your engagement dreams.

At Plum, we only use lab-grown diamonds because we believe they make better jewelry. You get better 4Cs without the environmental trade-offs of a mined diamond. Better for your conscience and your wallet.

Nervous about buying a ring online? Our Find Your Diamond Kit offers a free home try-on and ring sizer to make finding the dream ring a piece of cake!

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