All About Diamond Carats, Choosing Engagement Diamonds by Weight

In case you haven’t heard of the four “C’s”, guys, they are: Carat weight; Color; Clarity; and Cut. These are the four major points that need you need to be aware of when choosing an engagement diamond for your sweetheart. In this post I’m going to talk about the weightiest of the C’s: Diamond Carats.

Learning About Diamonds, One C at a Time

Most people when looking for a diamond start with carat which is the weight of the diamond. “I’d like the look at a one carat,” is commonly heard. And one carat is a nice size and a nice easy size. However there are things to know when you look for a diamond and weight is your first step. Read on.

Why it’s Called a Carat and Understanding Jeweler Jargon

Carat stems from the word “carob.” Imagine an ancient balance scale with a gemstone on one side and carob seeds on the other. Since each carab seed weighed the same, they were excellent for weighing purposes. Carat is abbreviated as ct. Today one carat weighs 0.2 grams.

Think of one carat as 100/100ths. So a .75ct diamond is 75/100ths of a carat, and also called a 3/4 carat diamond. And .25cts is 25/100ths of a carat or a quarter carat. It helps to know the various ways the weight is referred to. Jeweler’s might say, “Here’s a pretty half carater.” They mean it’s about a half carat.

What’s the Difference Between 1 Carat and 1 Carat Total Weight?

Total weight (TW.) refers to the combined weight of a number of smaller diamonds on a ring. So you could have a 1 carat (ct.) center diamond and .75cts Total Weight (TW.) of side diamonds.

The reason this is important to know, is that if you intend to get your girlfriend a one carat diamond and someone shows you a ring with lots of little diamonds and says, “it’s one carat,” it’s nice to know that they are referring to the total weight of all the diamonds on that ring. And not trying to fool you.

I have talked to guys who were crazy confused by this. Explaining this made their eyebrows go back to normal. One guy called a store to see if they had one carat engagement rings. The guy said, “we sure do and we have a special,” and named a very low price. My client went in and was shown a cluster of diamonds that was one carat in total. “Here’s the one carat diamond ring dude.” Yeah, No!

Luckily in addition to being a bunch of little diamonds which seemed wrong to him, they were very gray and cloudy. He showed me a picture. I congratulated him on not proposing with that cloudy awful ring.

How to Read the Diamond Ring’s Price Tag

The Price Tag on This Engagement Ring Would Say 1.10ct. RB/ .75cts. TW.(2) / .35cts. TW. Side.

So if the price tag on the engagement ring says; 1.12ct /.75cts.TW, it’s saying the center diamond weighs 1.12cts and the side diamonds weigh .75cts when weighed and added together. Whenever you see TW (total weight) know that this is an added up figure of multiple gems. TW never stands for a single gemstone.

A price tag that says 1.12ct/RB/.75cts TW RB/.35cts TW Bag would translate to 1.12ct Round Brilliant, your center gemstone, .75cts TW of Round Brilliant cut gemstones and .35cts. of Baguette cut gemstones.

Different jewelers use different abbreviations for different cut shapes. Ask how their abbreviation system works and the price tags will tell you a lot about each ring under consideration and will make it easier for you to compare each one realistically.

More Jeweler Talk, What Are Points?

Each carat is divided into 100 points. Thus, .50cts or a 1/2 carat, equals 50 points. A 3/4 carat size equals 75pts. So a Jeweler could write this about a half carat diamond: .50cts, meaning it is 50/100ths of a carat, but in conversation he’d say, “it’s a 50 pointer,” or “that’s a half carat” or she might say, “this is a half cararter.” It’s nice to know the talk, to better communicate with your jeweler.

Your jeweler may say, “this diamond that we’ll use on the side is 33 points.” The translation is this diamond is 33/100ths of a carat, or a third of a carat, or .33ct. They might also say, “this is a 33 pointer.”

The Price Per Carat and Why it Keeps You Guessing

The supply of diamonds is like a pyramid. At the bottom are the smaller diamonds. In other words there are a lot of smaller diamonds. As you move up the pyramid, the supply narrows and there are less diamonds available. The more scarce diamonds are the larger diamonds. Each aspect of a diamond in grading pushes that diamond into a certain pricing per carat. As I discuss later there are price jumps at 1ct, 2cts, 3cts, etc.

The factors that effect the price per carat are all four of the 4C’s. They are: Carat weight; Color; Clarity; and Cut. We focus in this blog on carat weight. I just wanted you to know that all four of the C’s come into play when pricing diamonds.

If you’re looking at a .50ct diamond and you say, “how much?” You might get the response, “this diamond is $3,000.00 per carat, or $1500.00.” You might be thinking, which one is the price?

Then a bit later you might be looking at a 1.10ct diamond and ask, “how much for this one?” Your jeweler might say, “Hmm, well this one is $7145,00 per carat,” they pull out a calculator and say, “this diamond costs $7860.00.” They smile. You cringe.

Diamond in Tweezers

Why is the price of the diamond more? The last one he seemed to be discounting from $3,000.00 to $1500.00. That’s what happened right? And this one he mentioned a price of $7145.00 and then said it cost $7860.00. Kind of a crap sales pitch you might be thinking. What’s really happening is, your jeweler is doing that jeweler talk thing, where they forget that you just learned what a carat is. Sort of. You think you get it. To ask you now to take the leap to price per carat is asking a lot. I get it.

I’ll try not to bore you here. Because the scarcity of diamonds happens in ranges they price diamonds by the carat in ranges as well. So that .50ct diamond was in the $3,000.00 per carat range. Your jeweler multiplies the weight of your diamond by the price per carat that number crunchers in special places determine. I don’t figure out the price per carat of your diamond. The diamond market gods determine that this cut is more scarce and in demand, and that color is more common and less in demand. And they write it down. And we jewelers pay for the privilege of seeing that data.

So the fact that the .50ct diamond is less expensive in it price per carat than the 1.10ct diamond, tells you that there are more .50ct diamonds out there than there are 1.10ct diamonds.

Let’s say you see a .57ct and you like that one too. You ask, “is that also $3,000.00 per carat?” Your jeweler looks it up and says, “why yes. It is the same.” Then he points to another diamond nearby and says,  “But this .65ct diamond is $3,200.00 per carat.”

Now that you are not confused by the concept of price per carat, can I just say that littler ones are way cheaper than bigger ones? And because of scarcity, a one carat diamond will be more than twice as much as a .50ct diamond.

Why Diamond Carats Total Weight, TW., is Different from Just Carats, When Buying

A one carat (1ct.) round brilliant cut diamond set in a simple four prong setting of medium quality, could cost you $5,000.00 to $6,000.00. That’s a ring with one diamond.

A one carat (1ct. TW.) round brilliant cut multi-diamond band ring might cost you $2000.00 to $3000.00. The smaller diamonds do not cost as much per carat as the larger single gem price.

Isn’t the Total Weight in my Girl’s Ring the Most Important Thing?

Her Rebuilt Ring With Strong Prongs and a Strong Shank to Support the Top.

Nope! Just know that the center or largest diamond in the engagement ring is the most important diamond in the ring. Don’t get romanced by a multi-diamond 3ct. TW. mish mosh of little diamonds with the largest gemstone weighing in at .30cts.

That may sound impressive, but a 1 ct. diamond at the center always trumps a bunch of little diamonds.

This doesn’t mean that she doesn’t want some of those nice side diamonds, just that you need to start with a large central diamond as the priority, then go for your accent diamonds.

That Magic One Carat Size

Whole numbers are magic numbers. What do I mean? I mean that many girls want the diamond in their engagement ring to be at least 1ct in weight. They want to know—and be able to tell their friends—that the diamond in their engagement ring weighs at least one carat.

Not “just under a carat.” Not 95pts. But a full on carat—or more! Got it? Don’t ask me why. That’s just the way it is.

This “Perfect Size/Weight” Diamond Demand, Results in Some Pricing Shenanigans

A sizable price jump occurs at 1ct. Other big price jumps occur at 2cts, 3cts, 4cts, etc. A full 2ct diamond will set you back a lot more money than a 1.90ct diamond will.

The thing is, Jewelers and diamond cutters know all about this desire for full carats by women, too. They know Julie wants the one carat diamond. She doesn’t want the 95 pointer. She wants the full carat.

That’s why diamond cutters who cut too many diamonds in weights like .95, .98 and .99 change professions. That’s also why there are far fewer barely-under-1 ct. diamonds than there are over-1 ct. diamonds.

The Price You Pay for That Full Carat Diamond

It means that diamond cutters and then Jewelers, charge a premium for a one carat diamond. All other aspects being equal, you will pay considerably more for 1.02ct diamond than you will for a .92ct one.

Sometimes to get that magic one carat size diamond cutting shenanigans happen. In the picture above, on the right, the cutter added useless depth at the girdle. (The widest point). The cutter got the extra weight. Don’t be the customer that buys this dreadfully cut diamond, just because it’s the right weight.

So You Still Have Choices in Diamond Weight

This means that a 1.00ct. diamond with crappy color and OK clarity and with little sparkle and pizzazz might cost considerably more than a sparkly diamond with perfectly good cut, nice color, and excellent clarity that weighs .85cts.

And here’s the kicker, I bet you can’t tell which is bigger! OK, I exaggerate, but you get my point.

It Can’t Hurt to Ask

Armed with this information, talk to your Jeweler. Maybe he will bring out the fabulous .92ct diamond that he was reluctant to show you because it was just under a carat.

Is One Carat a Certain Size?

There are different cutting styles and faceting patterns for cutting diamonds. For this reason, diamond carats are not a guarantee of a certain size when you measure the diameter of a diamond.

What’s a Guy to Do, Go First For Diamond Carats or the Other C’s?

So…what do you do? Don’t settle for a crappy looking diamond—whatever the weight. Spend a few more dollars for something with great color, and cut that will still sparkle and shine and look good fifty years from now.

Can We Talk?

If at all possible, talk to your sweetie. (Free advice: Communication is the key to a good marriage!) She may be fine with the 92 pointer. Not all women have to have the full carat—especially if it means bankrupting the family.

Nobody can tell the difference between five or eight points of diamond weight, anyway—especially once set in a ring.

Why Certificates Matter

I recommend GIA, Gemological Institute of America diamond grading reports. The number is etched on the girdle of your graded diamond. You can use the weight on the report to compare with the diamond you are looking at. Sometimes diamonds get switched around accidentally. Verify that your diamond is what they say it is. Checking the weight is an easy first step.

Why is the Price Not on the Diamond Grading Report?

Diamond prices change. This report is about the diamond. All four of the C’s in thorough detail. Each diamond is like a snowflake. It is individual. The grading report details the differences that make your diamond special.

Once you buy that diamond, take your diamond grading report to your appraiser and they’ll figure out it’s value in today’s dollars. Diamond prices fluctuate depending on the demand, in your case for the weight, shape, color and clarity of your diamond. Then insure the engagement ring. I wrote about insuring diamonds.

You Can Always Trade Up in Diamond Carats the Future

If You Use a Number of Smaller Diamonds, You Can Have a Big Carat Weight in Total Weight

Finally, lots of couples don’t have a lot of money when they’re first starting out and can’t afford a larger stone. Don’t worry. It’s all about the love…not the rock. Get something nice, but that you can afford.

Ten years down the line when you’re more established financially, you can always exchange the smaller diamond for a bigger one. Couples do this all the time.

Now you know a little about the weightiest “C”, diamond carats. You’re that much closer to being able to comfortably shop for an engagement diamond. Way to go!

Calla Gold
Diamond Seller and Educator

Also see my posts on:

Choosing diamonds by color:
Diamond color

Choosing diamonds by cut:

Diamond cut

Choosing diamonds by clarity:

Diamond clarity