The Definitive Guide to 1-Carat Diamonds

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by Suzanne Sachs  5 min read

Art deco Diamond Rings

The Definitive Guide to 1-Carat Diamonds

THE BASICS ---

A 1-carat diamond can be a beautiful gem, but what does it mean when a diamond is labeled as one carat? A better understanding of this critical measure of a diamond’s weight can help you be better prepared to choose the perfect diamond for an engagement ring, wedding band, anniversary ring, pendant, or any type of diamond jewelry.

NEED TO KNOW --

When purchasing a one-carat diamond ring, consider the shape, color, clarity, and millimeter size, keeping in mind that slight imperfections can affect its overall appearance. Additionally, think about the era and metal of the ring—whether you prefer a vintage design from a specific period, complete with its own unique imperfections, or a minimalist setting in gold, platinum, or another metal. Always choose a reputable jeweler to ensure the authenticity and quality of the diamond, as well as the craftsmanship and materials used in the ring.

Table of Contents

  • What Is A Carat?
  • What Weighs One Carat
  • Variations On One Carat
  • One Carat Diamond Cost
  • How Settings Impact Carat Weight
  • Understanding Total Carat Weight
  • Frequently Asked Questions
  • Is Bigger Always Better?

What Is a Carat?

A carat is the standardized international unit of measurement for diamond and gemstone weight. One carat is equal to 200 milligrams, or one-fifth of a gram. Carat measures were first standardized in the 1570s, though not to the precision of today’s 200-milligram measurement. Instead, carat weight was originally associated with the weight of carob seeds—edible seeds from a flowering tree widespread throughout the Mediterranean and Middle East regions. These seeds are quite uniform in shape and size, making them ideal for use as counterbalances when gemstones were weighed.

In 1907, the precise modern measurement of one carat was adopted, and many countries use this measurement today. Carat measurements are also described in points, with a full 1-carat diamond being described as 100 points. For example, a 25-point diamond weighs one-quarter of a carat, a 50-point diamond is half a carat, and so on.

Diamond Shape Length (mm) Width (mm) Depth (mm)
Round Brilliant 6.5 6.5 4.0
Princess Cut 5.5 5.5 4.0
Emerald Cut 6.0 4.0 3.0
Oval Cut 7.7 5.5 3.5
Marquise Cut 10.0 5.0 3.5
Pear Cut 8.5 5.5 3.5
Cushion Cut 5.5 5.5 3.8
Asscher Cut 5.4 5.4 4.0
Radiant Cut 6.0 4.5 3.5
European Cut 6.4 6.4 4.0

What Weighs One Carat?

While knowing the technical measurement of one carat is helpful, what does that weight really mean? A weight of 200 milligrams may sound like a lot, and for such a rare substance as a precious gem, it is significant.

In comparison, a 200-milligram pill – a standard dosage of basic aspirin, for example – is also equal to one carat. Few other items are as light, but a one-carat diamond is also the same weight as one-fifth of a United States dollar bill, one-fifth of a business card, one-fifth of a standard paper clip, or one-quarter of a raisin. Despite their small size, however, diamonds have big, incomparable beauty.

To bring a carat’s size into perspective, it would take approximately 2,250 one-carat diamonds to weigh a full pound!

Vintage Diamond Filigree Engagement Ring GIA .99 H/VS1  in Platinum

Variations on One Carat

Not all 1-carat diamonds look the same. The shape of the diamond, as well as the proportions of its cut, can dramatically influence how visually large or small the stone may appear. Longer shapes such as oval, emerald, marquise, and pear tend to emphasize carat size and look bigger, while deeper shapes such as heart, cushion, and princess tend to look smaller even if the weight measurements of the stones are identical.

The cut of a diamond, as well as the stone’s clarity and color, also impacts how visually large a stone may seem to be. A higher quality stone with a precise cut will refract more light, increasing its sparkle and interior fire for a larger appearance. Similarly, the more colorless the stone may be, the better it will internally refract light for better fire and a larger look.

    Circa 2000 Vintage Marquise Diamond Three Stone Engagement Ring GIA 1.09 Ct I/I1 Center

One Carat Diamond Cost

There is a great price range in the cost of a 1-carat diamond. Depending on the stone’s overall quality – all four C’s, not just carat – the cost may be as little as $1,000 or as high as $25,000 or more. Couples on a budget can investigate some cost-saving options to purchase a good 1-carat diamond by choosing a stone with slightly less precision in its cut, a lower quality color, or internal flaws to its clarity that reduce the price.

Another way to affect the price of a 1-carat diamond is to get a nearly, but not quite, 1-carat stone. There is virtually no difference in size between a .95-carat diamond and a 1-carat diamond to the casual eye, yet the price difference between the two sizes can be significant, even when the stones are comparable in other quality assessments.

How Setting Impacts Carat Weight

A ring’s setting can also impact the appearance of a diamond’s overall carat weight. A 1-carat diamond set in an elevated, open setting such as a cathedral prong style or a sleek modern tension setting will have more light enter the stone for greater refraction, making the stone appear larger. A closed, confined setting such as a bezel or channel setting, on the other hand, keeps more light out of the stone and limits refraction, therefore making the stone appear somewhat smaller.

 

Art Deco Bezel Set Old European Cut Diamond Engagement Ring GIA 1.12 G/I1

 

 

Understanding Total Carat Weight

Another measure buyers need to be aware of is the difference between an individual diamond’s carat weight and the total carat weight of a piece of jewelry. An individual stone’s carat weight measures just that one stone, no matter what type of jewelry it is part of, how it is shaped or cut, or what quality the diamond may be.

Total carat weight (TCW) refers to the combined, collective weight of all diamonds in a single piece of jewelry or matched jewelry set, such as a pair of earrings or a bridal wedding ring set that includes an engagement ring and an accented wedding band. This measurement does not take into account the individual weights of stones, but only the total weight when all stones are added together. A 1-carat
solitaire diamond, then, is certainly larger than a 1-carat TCW three-stone diamond ring, which splits that weight among all three stones rather than concentrating it into a single gem.

Total carat weight will include every diamond of any size in a particular piece, from a larger center stone to accents, side stones, halos, clusters, and even small chips that may make up a pave design. This can make TCW quite misleading, but it is still a valuable measure for a piece of jewelry overall.

Frequently Asked Questions

What is a 1-carat diamond?

A 1-carat diamond is a gemstone that weighs exactly 200 milligrams, or 0.2 grams, and typically measures around 6.4 to 6.5 millimeters in diameter if it's a round brilliant cut. The millimeter size can vary depending on the diamond's shape and cut quality, with some shapes like oval or marquise appearing larger due to their elongated forms.

Does a 1-carat diamond always look the same size?

No, the appearance of size can differ based on the diamond's shape, cut quality, and setting. Some cuts, like oval or marquise, may appear larger than a round cut of the same carat weight.

What is the best setting for a 1-carat diamond?

The best setting depends on personal preference and the diamond’s shape. Popular settings for 1-carat diamonds include solitaire, halo, and three-stone settings.

Our top 1-carat diamond ring pick

When selecting a 1-carat diamond ring, consider the diamond's clarity, size, and color, as well as the ring's quality, design, and era, to ensure it reflects your personal style and flair.:

• Vintage Diamond Filigree Engagement Ring GIA .99 Ct H/VS1

This stunning vintage diamond engagement ring from the Art Deco era, circa 1930s, features a GIA-certified 0.99-carat old European cut diamond of H color and VS1 clarity. Expertly crafted in gleaming platinum, the ring is beautifully accentuated with delicate open metalwork and intricate engravings.


Is Bigger Always Better?

A larger carat weight for a diamond isn’t necessarily a “better” stone by every measure. While a full carat is one of the most popular weights for diamond jewelry, particularly engagement rings, smaller stones of better color, clarity, and cut can be more attractive and valuable than full carat stones with other poor qualities or excessive flaws. Many of these qualities, however, are subjective, and the stone that appears perfect to one individual may not be quite so attractive to another.

To properly value a diamond, it is critical to assess all four quality C’s – carat, color, clarity, and cut. This will provide a thorough overview of the stone and a way to compare it objectively with similar diamonds. Ultimately, however, the beauty of a diamond is a personal preference, and any 1-carat diamond can be a stunning focal point for a piece of meaningful and mesmerizing jewelry. Ready to find your perfect 1-Carat diamond ring? Explore our 2024 collection and discover the vintage ring that speaks to your unique style.

Antique Engagement Rings For Everyone:

No matter which gemstone is your favorite, these time-honored rings have a rich history and individualized character and will continue to have a timeless beauty and elegant appeal that is part of a legacy to pass on to future generations.

Find The Perfect Engagement Ring:

Vintage rings are prized not only for their beauty but also for their exquisite attention to detailing and design. If you’re looking for a ring with a sense of glamour, sophistication and vintage charm, explore our collection of One Carat Diamond Rings today!

Suzanne Sachs

Suzanne has always believed vintage rings can change lives. She's been in the jewelry industry for over 35 years, working with vintage jewelers, diamond dealers, diamond cutters, and gemologists. Suzanne started Artdecodiamonds in 2000 and understood the demand for vintage rings throughout the world. She ultimately started VintageDiamondRing.com in 2014, and understands each vintage ring is a reflection of you – your history, your relationships, your style, your elegance and is honored to have the opportunity to help you showcase your flair in a unique and exquisite way.
 

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Art Deco Emerald Ring

 




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