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Diamond Shapes & Cuts: Wholesale Guide for Jewelers

Guru Diam October 15, 2026

Updated Oct 16, 2026 9 min read

Shape drives most design decisions. The center diamond sets the outline of a ring, and side diamonds such as trapezoids, baguettes and half moons have to match it in size and color. Guru Diam stocks 10,000+ IGI and GIA certified diamonds across the classic shapes and so many antique and fancy cuts, in natural and lab-grown.

This hub puts our shape guides in one place. The wholesale guides explain how each cut is built, which proportions to check and what it is usually set in. The comparison articles put two shapes next to each other, such as oval against emerald or round against cushion, so you can help a customer choose. The antique-cut section covers old mine, old European, rose and Portuguese cuts, which are priced differently from rounds.

Pairs and colors have their own sections. We match pairs to within 0.1 to 0.2 mm and about one color grade. Lab-grown pairs are available in all shapes, and natural pairs are made to order. Fancy color diamonds come in seven colors: black, blue, brown, green, pink, red and yellow. If a design needs a shape we don't have in stock, we can source it or cut it to your specification.

Most buyers who land here are sizing side diamonds. The trapezoid guide covers step and brilliant trapezoids and how to size a pair against a center diamond. The baguette, tapered baguette, half moon, shield and bullet guides do the same for other side shapes. For centers, the comparison articles cover oval vs emerald, round vs cushion, cushion vs princess, pear vs marquise and more, and the quick comparison article puts cushion, princess, Asscher, round and radiant side by side. Shape names in these guides match the names on our listings, so any shape you read about here can be found on the certified diamonds page.

Sourcing for vintage or estate work? See old mine cut and antique lab-grown diamonds for vintage and estate dealers.

Shop diamonds by shape

Certified lab-grown diamonds · Exotic fancy shapes · Antique and fancy color wholesale · Matching pairs · Fancy color certified diamonds · Natural certified diamonds · Fancy layouts

Start here: the most-read shape guides

Trapezoid Diamond Guide: Trapezoid side diamonds: step and brilliant versions, sizes, and how to pair them with a center.
Oval vs Emerald Cut Diamond Guide: How the two shapes differ in look and spread.
Antique Cut Lab Grown Diamonds Wholesale: Old mine, old European and other antique cuts in lab-grown.
Old Mine Cut vs Old European Cut Wholesale Guide: How to tell the two classic antique cuts apart.
How Antique Exotic Cuts are Priced Differently from Round: Why antique and exotic cuts don't follow round pricing.
Matched Pairs Lab Grown Diamonds Wholesale: How we match pairs for earrings and side diamonds.
Fancy Color Lab Grown Diamonds Wholesale: Fancy color lab-grown diamonds by color and shape.
Baguette Diamonds Wholesale: Baguettes for side and channel work.
Lozenge Diamonds Wholesale: Lozenge cuts and where they fit in a design.
Types of Diamond Cuts Guide: An overview of the main shapes and cut styles.

Diamond shapes and cuts: wholesale guides

Diamond shape comparisons

Fancy color diamonds

Matched diamond pairs

Antique and old cut diamonds

Diamond shape questions from the trade

What is a trapezoid diamond?

A trapezoid is a four-sided diamond that is wider at one end. It is used mostly as a side diamond on either side of a center, and it comes in step-cut and brilliant versions.

Which shapes do you stock?

We stock 10,000+ IGI and GIA certified diamonds in round, oval, cushion, emerald, pear, radiant, princess, marquise and Asscher, plus so many fancy and antique cuts. The certified lab-grown page lists every shape.

How closely are matched pairs matched?

Pairs are matched to within 0.1 to 0.2 mm and about one color grade. Lab-grown pairs are available in all shapes. Natural pairs are made to order.

Which fancy colors are available?

Seven: black, blue, brown, green, pink, red and yellow.

Can you cut a shape you don't have in stock?

Yes. We source or cut diamonds to a buyer's specification, including custom shapes.

Next step

Browse certified diamonds by shape or open a trade account to see prices and NY or LA stock.

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