A Cut Above: Your Ultimate Guide to Diamond Shapes (with Pro Buying Tips)
At The Carat Commons, we believe in making the diamond world more transparent, accessible, and radically fair. That means giving you the knowledge traditional jewellers often gatekeep.
If you're shopping for a lab-grown diamond—whether loose or in a custom engagement ring—the cut is one of the most important factors in both look and price. But when people talk about a “diamond cut,” they’re often referring to two things at once:
The shape of the diamond (round, oval, emerald, etc.)
The cut quality, or how well the diamond reflects light (graded as Excellent, Very Good, etc.)
This guide breaks down all the most popular diamond shapes offered at The Carat Commons, including what they’re best known for and three practical tips to help you buy smarter.
Round Brilliant Cut: Classic Sparkle and Maximum Fire
Round brilliant cuts are the most popular diamond shape on the market and dominate the jewellery industry for a reason. With 57 or 58 perfectly engineered facets, this shape offers the highest level of brilliance, light return, and timeless appeal.
Top 3 Tips for Buying a Round Brilliant Cut
Prioritise Excellent or Ideal cut grades for maximum sparkle—cut is the #1 value driver.
You can go lower on colour (G–H) since strong light performance masks any warm tones.
Inclusions are often hidden by the sparkle—VS2 or even SI1 can appear eye-clean.
Oval Cut: Elongated, Elegant, and Looks Larger Per Carat
Oval diamonds are loved for their flattering elongated shape and larger face-up appearance. They offer similar brilliance to round cuts but with a more unique and vintage-inspired silhouette.
Top 3 Tips for Buying an Oval Cut
Avoid shallow or overly wide cuts that create a visible bow-tie shadow.
Inclusions are more visible in the open face—aim for VS2 or better clarity.
Colour shows at the tips—F–G colour grades provide a whiter appearance.
Emerald Cut: Step-Cut Sophistication With a Minimalist Edge
Emerald cut diamonds offer clean, architectural lines and broad flashes of light rather than sparkle. This shape is favoured by those drawn to understated luxury and vintage refinement.
Top 3 Tips for Buying an Emerald Cut
Clarity is critical—aim for VS1 or higher since inclusions are easily seen in the large, open table.
Colour shows clearly in step cuts—F–G grades are ideal for a crisp, clean appearance.
Prioritise excellent symmetry and polish for a balanced, mirror-like finish.
Radiant Cut: The Sparkle of a Round in a Modern Shape
Radiant cut diamonds combine the elongated shape of an emerald with the brilliance of a round. Their brilliant faceting and cropped corners offer intense sparkle and durability.
Top 3 Tips for Buying a Radiant Cut
Choose stones with a depth between 61–67% for optimal light return.
Radiants hide inclusions well—SI1 clarity is often more than sufficient.
Colour is forgiving—H and even I grades can face up white, especially in yellow gold settings.
Cushion Cut: Vintage Romance With a Soft Edge
Cushion cut diamonds, also known as pillow cuts, come in both square and rectangular varieties. Their soft corners and gentle sparkle make them a romantic choice for antique-inspired or halo designs.
Top 3 Tips for Buying a Cushion Cut
Decide between vintage-style chunkier facets or modern “crushed ice” brilliance.
Cushion cuts can show warmth—G or better colour grades are safest for a bright appearance.
Inclusions can be hidden well—SI1 to VS2 clarity can still face up clean.
Princess Cut: Contemporary, Geometric and High Sparkle
The princess cut is a square-shaped diamond with pointed corners and strong brilliance. It's a great choice for those wanting a modern look at a lower cost per carat compared to round diamonds.
Top 3 Tips for Buying a Princess Cut
Use a secure four-prong setting to protect the sharp corners from chipping.
These cuts hide inclusions well—SI1 or better is often suitable.
G–H colour grades still look white in this bright, brilliant-cut shape.
Pear Cut: Unique Teardrop Shape With a Dramatic Look
Pear cut diamonds combine the best of the round and marquise cuts. Their elongated form can slim the fingers and offer excellent brilliance when well-proportioned.
Top 3 Tips for Buying a Pear Cut
Prioritise symmetry—both sides of the teardrop should match perfectly.
Bow-tie shadows are common—look for slightly deeper stones with better faceting.
Colour tends to concentrate at the tip—F–G colour grades offer better balance.
Marquise Cut: Bold, Elongated and Value-Focused
Marquise diamonds offer one of the largest face-up sizes per carat and are a great way to maximise presence on a budget. This vintage shape has a distinctive pointed silhouette that’s back in style.
Top 3 Tips for Buying a Marquise Cut
Look for a balanced length-to-width ratio between 1.75–2.15 for elegant proportions.
Marquise shapes hide inclusions well—VS2 or SI1 can still appear flawless.
Colour is more visible at the tips—G or better colour grades recommended.
Asscher Cut: Art Deco Style With Step-Cut Depth
Asscher cuts are square step-cut diamonds with clipped corners, creating a hypnotic “hall of mirrors” effect. They are bold, symmetrical, and full of vintage appeal.
Top 3 Tips for Buying an Asscher Cut
Clarity is critical—choose VS1 or better to avoid visible flaws.
Colour is easily seen—F–G is ideal to maintain a bright white look.
Make sure symmetry and depth are optimal to avoid a dull, lifeless stone.
Heart Cut: Symbolic and Sentimental
Heart-shaped diamonds are bold, expressive, and perfect for romantic gestures. They require expert cutting and are best showcased in larger sizes where the shape is clearly visible.
Top 3 Tips for Buying a Heart Cut
Choose 1 carat or larger to ensure the heart shape is visible and defined.
Prioritise perfect symmetry—uneven lobes or an undefined cleft reduce visual appeal.
This shape hides inclusions well—VS2 or even SI1 can still work beautifully.
Trillion Cut: Angular and Attention-Grabbing
Trillion cut diamonds are triangular and often used as accent stones, but can also be a bold centrepiece. They have excellent face-up size and offer a sharp, modern aesthetic.
Top 3 Tips for Buying a Trillion Cut
Make sure it’s set securely—pointed corners are vulnerable without protection.
These cuts hide inclusions fairly well—VS2 or SI1 clarity is usually suitable.
Avoid overly shallow cuts, which can reduce light performance and sparkle.
Baguette Cut: Sleek, Minimalist, and Low Sparkle
Baguette diamonds are step-cut rectangles known for their clean lines and quiet elegance. Most often used as side stones or in eternity bands.
Top 3 Tips for Buying a Baguette Cut
Inclusions are easily seen—clarity should be VS1 or better.
When used in multiples, colour matching is key—select stones in the same grade.
Baguettes work best when paired with high-sparkle centre stones like rounds or cushions.
Why Cut Matters When Buying Lab-Grown Diamonds
At The Carat Commons, we specialise in high-grade lab-grown diamonds that offer better value, ethical sourcing, and transparent pricing. But even with lab diamonds, cut quality is essential.
Each shape behaves differently under light—and choosing the right cut means getting the most brilliance, size appearance, and beauty for your budget. That’s why we vet every diamond in our collection or custom sourcing process with strict cut quality standards.
Choosing the Right Diamond Cut With The Carat Commons
Whether you're browsing our curated loose diamonds or using our custom sourcing service, our goal is to make your buying process simple, ethical, and exceptional. We’ll walk you through:
What shapes look largest for their carat
Which cuts hide flaws and offer better value
How to balance cut, colour and clarity for lab-grown diamonds
How to pair a cut with a setting that enhances its beauty
We don’t sell markups, middlemen, or mass-produced sparkle. We sell diamonds without the delusion—honest pricing, custom experience, and radically high standards.
Explore more with The Carat Commons.
Loose lab-grown diamonds. Custom rings. No industry markup.
Ready to find the right cut for you? Start browsing our collection.