Are you buying a diamond? What do you need to know to be a savvy diamond shopper? It all starts with the “4 Cs” of diamonds. Master the 4 Cs, and you’ll be well on your way to choosing the best diamond for your budget.


This article refers to GIA throughout. GIA stands for the Gemological Institute of America. GIA is a nonprofit institution committed to protecting and educating the public in the field of gems and jewelry. GIA created the 4 Cs to describe the characteristics of a diamond and is an excellent resource for consumers.

GIA diamond cut diagram


Diamond cut refers to how a diamond is faceted and how those facets reflect light, not the shape of the stone (round, princess, emerald, etc.) Cut is an important characteristic to consider when choosing a diamond and has the most impact on a diamond’s sparkle.

A well-cut diamond will have more fire and brilliance and generally look larger. A poorly cut diamond will look, well, pretty much the opposite.

Diamond cut is measured on a 5-range scale from excellent to poor.

Learn More About Diamond Cut from GIA


Diamond color is measured on a scare from D-Z, and measures the lack of color in a diamond.

Pro Tip: Color will be more visible in larger diamonds. Settings can also impact color. A white gold setting will make a diamond with more color look more yellow, or a colorless diamond look icier. A diamond with more color will often look better in a yellow gold setting. 

Learn More About Diamond Color from GIA

GIA diamond color diagram
GIA diamond clarity diagram


Clarity measures the presence or absence of inclusions in the diamond. Inclusions are tiny imperfections in the diamond, kind of like birthmarks. There are many different types of inclusions, but the good news is that most aren't visible to the naked eye.

Pro Tip: Very slightly included and very very slightly included diamonds are often the best value, and inclusions in this range are almost always only seen under 10x magnification.

Learn More About Diamond Clarity from GIA

Carat Weight

Diamonds are measured by their weight, not the physical size of their dimensions, and a diamond's carat weight has the most significant effect on price. That being said, bigger is not always better when it comes to diamonds. A diamond's shape and cut play a big part in how large a diamond will look.

Pro Tip: Buy "shy." A 1.90 carat diamond will cost considerably less than a 2.00 carat diamond, and the size difference will be barely noticeable. Also, keep the ring size in mind when choosing a diamond. A diamond will look larger on a ring size 6 than on a size 8.

To Learn More About Carat Weight from GIA

GIA diamond carat weight diagram
GIA diamond grading comparison

Limitations of the 4 Cs

Like snowflakes, each diamond is 100% unique. Because each diamond is unique, two diamonds graded the exact same will look slightly different. This is where buying a diamond in person becomes important. Compare two or more similar diamonds can be an invaluable step in choosing the perfect diamond for your taste and budget.

This is one of the most significant downsides to buying a diamond online, and the biggest upsides to buying in person.

Wrap Up

There is a ton of information out there about the 4 Cs. We've given you the basics that everyone should know before buying a diamond. If your curiosity is peaked, click on the links to the GIA articles to go more in-depth on each "C."

Our experienced team is always available to answer your questions. Store manager Lex Harrison is a GIA Graduate Gemologist, one of the most prestigious credentials in the jewelry industry, and is an excellent resource when choosing diamonds. Park City Jewelers has the experience and expertise to help you choose a diamond that will be cherished for a lifetime.


430 Main St Park City, UT 84060

Phone: Call or Text!

(435) 649-6550