Have you had your eye on a particular diamond, but you have no idea how much it costs? That’s not surprising. Diamond prices are complicated; there are so many factors that go into the price from the cut to the origins to the carat. It’s hard to figure out the price of a diamond without asking a jeweler, and even then, how do you know you are getting a fair or competitive estimate?

To help answer all your questions, we turned to jeweler Anna Jay. She explained how much a diamond costs on average and what determines its price. She also gave advice on how to find the right diamond for your budget. Read on to learn more.

Average Cost by Carat

People often assume a diamond’s cost is determined by its carat (weight), but that isn’t true, reveals Jay. “There are so many factors that impact the price of a diamond, including shape, clarity, and color,” she explains. That means that even if a diamond is the same carat as another, it might not have the same price. “Natural round diamonds tend to be about $6,000 per carat, but that doesn’t mean there aren’t one-carat diamonds that are $1,000 or $15,000,” she says. “It all depends on the quality of the diamond you are purchasing.” The good news is that if you want a diamond with a particular carat, and that is the most important factor for you, you can find one at a range of prices.

Another common mistake people make is to assume the price scale of diamonds is linear (i.e. a two-carat diamond will be worth twice the amount of a one-carat diamond.) “The diamond price scale is exponential, not linear,” Jay explains. That is why diamonds are tricky, and it might be a good idea to work with an expert to determine which diamond is the best fit for you. “Working with [a jeweler] allows you to see diamonds that are exactly within your goals of size, budget, and quality.”

Factors That Determine Diamond Cost

A lot of people are aware of four factors, known as the 4Cs, that help determine a diamond’s cost. They are carat (weight); color (Diamonds come in all sorts of colors, including red and purple!); clarity (Are there defects or blemishes?); and cut (round, princess, emerald, etc.) But there are also other lesser-known factors such as what material the diamond is made of, what the cutting style is, and how square or rectangular a diamond is.

“The general rule of thumb is that the [rarer] it is—think higher color, larger carat weight, and higher clarity—the more expensive it will be,” says Jay. “For a natural diamond to be created over millions of years, brought to the surface, and then subsequently found, have enough fine qualities to be cut and polished is incredibly rare.” That means if you want a diamond that is D-colored (which means it has no color like glass) or naturally blue, green, pink, or yellow, you are going to pay a lot more. “These diamonds are much [rarer] and therefore expensive on a price per carat basis than their colorless counterparts.”

How to Know If You’re Paying the Right Amount for a Diamond

You may be thinking, if the cost of a diamond is so complicated and can change based on so many factors, how do I know if I am paying the right amount?

Jay says the best way forward is to do your research and know exactly what you are purchasing. Compare the price of diamonds that have many of the same qualities—the same clarity, cut, and carat, for example—and ask a lot of questions about the qualities of your particular diamond and how it differs from cheaper or more expensive ones. “By understanding what you’re purchasing, you’ll understand the value and subsequently the price,” she explains.