THE NETCARAT DIAMOND GUIDE

A little knowledge. A brilliant choice.

Discover what makes every diamond different—from the 4Cs to the silhouette you love. Understand the details, then choose with confidence.

Discover the 4Cs

01 / UNDERSTAND THE DETAILS

Four characteristics.
One unique diamond.

Cut, color, clarity and carat weight help describe a diamond. Consider them together, alongside its shape and appearance, rather than choosing by one grade alone.

01

Cut

HOW THE DIAMOND INTERACTS WITH LIGHT

Cut considers proportions, facet arrangement and finish. These influence brightness, fire and the pattern of sparkle as the stone moves.

GIA’s standard cut grades apply to eligible round brilliant diamonds. Fancy shapes need an assessment of their appearance, proportions and finish rather than assuming the same cut scale.

ExcellentVery GoodGoodFairPoor

Cut is different from shape. Compare the diamond in more than one lighting environment.

02

Color

UNDERSTANDING BODY COLOR

The GIA D-to-Z scale describes increasing yellow or brown body color in the conventional color range. D represents colorless; later letters indicate progressively more visible color.

Fancy-color diamonds are assessed differently. Small grade differences may be difficult to see without controlled comparison.

D–FG–JK–MN–RS–Z

Consider the appearance of the actual diamond, along with its setting, rather than the letter alone.

03

Clarity

INCLUSIONS AND SURFACE CHARACTERISTICS

Clarity describes internal inclusions and external blemishes. Graders consider their size, nature, position, number and visibility under 10× magnification.

The natural-diamond GIA scale spans 11 grades, grouped into Flawless, Internally Flawless, Very Very Slightly Included, Very Slightly Included, Slightly Included and Included.

FLIFVVS1–2VS1–2SI1–2I1–3

Ask how the characteristics affect the specific stone’s appearance and durability. A grade alone does not guarantee an eye-clean appearance.

04

Carat

WEIGHT, NOT A FIXED FACE-UP SIZE

One metric carat equals 0.2 grams. Carat weight is a measure of mass, rather than a direct measurement of the diamond’s width.

Two diamonds of equal weight can differ in visible size because of their shape and proportions. The report’s millimeter measurements help you compare their dimensions.

0.50 ct1.00 ct1.50 ct2.00 ct

Carat describes a gemstone’s weight; karat describes gold purity. They are different measurements.

The grade scales above describe conventional natural-diamond grading. Laboratory-grown report terminology can differ by laboratory and report date.

02 / FIND YOUR SILHOUETTE

A shape for your style.

Shape describes the outline. Cut describes how the diamond’s facets interact with light. Explore the silhouettes below, then view the individual stone in photographs or video.

Round

A circular brilliant silhouette with a balanced, familiar appearance.

Oval

An elongated, rounded outline with brilliant-style faceting.

Emerald

A clipped rectangular silhouette with stepped, mirror-like facets.

Pear

A rounded end and a pointed tip create a distinctive teardrop outline.

Cushion

A square or rectangular silhouette softened by rounded corners.

Princess

A square outline with pointed corners and brilliant-style faceting.

Marquise

An elongated silhouette tapering to a point at each end.

Radiant

A square or rectangular shape with clipped corners and brilliant-style facets.

Asscher

A clipped square silhouette with geometric step-cut facets.

Diagrams are illustrative and are not to scale. Faceting patterns vary between individual diamonds.

03 / KNOW YOUR DIAMOND

Different origins.
Both diamond.

Natural and laboratory-grown diamonds share diamond’s essential chemical composition and crystal structure. Their origin differs, and identifying that origin requires specialized gemological testing.

NATURAL

Formed in the earth.

Natural diamonds originate through geological processes. Review the individual stone’s quality details and its grading report, rather than assuming that origin alone describes its appearance.

LABORATORY-GROWN

Created through technology.

Laboratory-grown diamonds are produced using technologies such as HPHT or CVD. Review the stone and its specific report; quality terminology can vary by laboratory and report date.

Diamond simulants are a different category.

Moissanite and cubic zirconia can resemble diamonds, but they have different compositions and properties. They are not laboratory-grown diamonds.

04 / READ BEYOND THE LABEL

Know what your
report tells you.

A gemological report gives you a documented description of a stone. Read the actual report, identify the issuing laboratory and confirm its number using the laboratory’s verification service.

01

Confirm the identity

Check the report number, laboratory and whether the stone is natural or laboratory-grown. Use the issuing laboratory’s report-check service.

02

Read the measurements

Review shape, dimensions and carat weight. Two stones with the same weight can have different face-up dimensions.

03

Review the assessment

Look at the applicable quality grades or descriptions, finish and comments. A report supports comparison; photographs and viewing the stone add useful context.

04

Understand the document

A grading report describes the stone. It is not an appraisal of monetary value or a promise of future resale value.

05 / CHOOSE WITH CONFIDENCE

Your diamond checklist.

01

Start with your style

Choose a silhouette and setting that suit the way you want to wear your jewelry.

02

Compare the whole stone

Review the appearance, dimensions and quality details together.

03

Confirm the details

Check the diamond’s origin, report, metal, ring size and any customization.

04

Review the purchase terms

Read delivery, returns and service policies before completing your order.

06 / CARE FOR THE DETAILS

Keep the brilliance.

  • Ask for cleaning guidance suited to your diamond, any treatments, other gemstones and the setting.
  • For suitable diamond jewelry, mild soap, warm water and a soft brush can remove buildup.
  • Avoid bleach and abrasive cleaners. Ask a jeweler before using an ultrasonic cleaner.
  • Store pieces separately and have a jeweler check loose stones or damaged settings before wearing them.

A LITTLE MORE KNOWLEDGE

Your questions,
answered.

Is cut the same as shape?

No. Shape is the diamond’s outline, while cut considers the faceting and its interaction with light.

Are laboratory-grown diamonds diamond?

Yes. They share diamond’s essential chemical composition and crystal structure, but have a different growth origin. Simulants such as moissanite are different materials.

Does a higher carat weight always look larger?

Not necessarily. Shape and proportions influence face-up dimensions. Compare the millimeter measurements and appearance of the individual stones.

Does every diamond report use the same grades?

No. Laboratories and report types can use different terminology. Since October 2025, GIA’s revised D-to-Z laboratory-grown service uses an overall Premium or Standard assessment. Check the report type and date.

Does a grading report tell me the diamond’s price?

A grading report describes characteristics of the stone. It is not a monetary appraisal. Ask separately about price and purchase terms.

LET’S FIND YOUR DIAMOND

Your next chapter starts here.

Explore the collection or speak with our team about the details that matter to you.

Continue learning with GIA:

Diamond qualityDiamond shapesLaboratory-grown assessmentsDiamond care