4 Carat Lab Grown Diamond Price: Examples and Comparisons

The following examples cover round loose diamonds weighing 4.00–4.01 carats. All three sellers’ listings identify IGI reports. Prices and listing status were reviewed on 11 September 2026.

Price basis: These are public retail loose-stone listings, not Uniglo quotations or completed ring prices. The Ritani pages displayed ordering options; Whiteflash described its stone as in stock. Availability requires seller confirmation. Tax inclusion was not established from the product pages, so these amounts should not be treated as tax-inclusive delivered totals. Whiteflash separately displayed a US$6,208 wire-transfer price; the table uses its standard advertised price.

This small selection does not establish a market minimum, maximum or average. It also does not show that every diamond with the same grades should cost the same amount. Other shapes, cutting styles, suppliers and purchase terms can produce different quotations.

For the wider pricing framework across weights, visit our lab grown diamond prices guide.

The two D/VS1 examples are a useful starting comparison because their weights are almost identical and their advertised colour and clarity grades match. However, they are different stones with different measurements and offers. Whiteflash places its example within its Precision Lab collection and supplies information about its cutting and optical precision. The price difference alone does not establish how much is attributable to cutting, stock selection, service or seller margin.

When evaluating a higher quotation, ask the supplier to explain the difference using evidence for the actual diamond. Useful evidence includes the grading report, a clear video, relevant light-performance imagery and an explanation of the inspection and return terms.

Also compare the same price unit. A quotation of US$1,510 for a 4.00 carat stone works out at US$377.50 per carat. A supplier quoting per carat must multiply that figure by the diamond’s actual weight to give the complete stone price. Mixing these two units can make quotations appear much further apart than they are.

Carat measures weight. It does not specify a diamond’s diameter or the area visible from above. Shape and proportions determine how that weight is distributed, so two four-carat diamonds can have different dimensions. GIA’s diamond quality guidance.

In the examples above, the 4.00 carat D/VS1 round has listed diameters of 10.18–10.27 mm, while the 4.01 carat D/VS1 round measures 10.11–10.17 mm across. The slightly heavier stone therefore has smaller listed diameters. This comparison demonstrates why paying for additional weight does not automatically buy more visible size.

However, greater diameter does not establish better cutting. A diamond’s proportions also affect how it returns light, and a larger outline is less useful if its appearance disappoints. Compare dimensions alongside brightness and contrast rather than selecting the widest stone from a spreadsheet.

For oval, emerald, radiant and other elongated shapes, compare length, width and depth. An oval’s longer outline creates a different visual impression from a round diamond, but its appearance also depends on its facet pattern and bow-tie effect. Examine it in motion rather than judging it from a single bright photograph. GIA’s oval diamond guide.

Our diamond shapes guide explains the different outlines and cutting styles.

There is no automatic requirement to choose D colour or VVS clarity simply because a diamond weighs four carats. The practical question is whether an alternative grade changes the appearance in a way that matters to you.

Clarity assessment considers the size, number, position, nature and visibility of inclusions. A grade should therefore be read alongside the characteristics of the individual stone. An inclusion beneath the table can present a different concern from one near the edge. GIA’s explanation of clarity factors.

For colour, compare shortlisted stones under consistent lighting and consider the intended jewellery design. Ask what visible improvement a more expensive grade offers in that comparison. Avoid paying a premium solely because a grade has been presented as essential for every large diamond.

If you are considering VS clarity, request an assessment of whether inclusions are visible without magnification and ask about the viewing conditions used. A seller’s “eye-clean” description is more useful when its meaning is explained.

An IGI laboratory-grown diamond report documents identifying and grading information, including measurements and the diamond’s laboratory-grown origin. It provides a basis for comparing specifications, but it is not an appraisal of the selling price. IGI’s laboratory-grown diamond report guidance.

Before accepting a quotation, match its report number, weight, shape, colour, clarity and measurements to the report supplied. Check whether a term such as “Ideal” refers to a grade on that report or the retailer’s own classification. Similar marketing labels should not be assumed to represent identical assessment standards.

For help with the report itself, read our IGI lab grown diamond report guide.

A public retail listing and a wholesale quotation describe different purchasing arrangements. A trade quotation may depend on quantity, payment timing, inspection conditions and delivery arrangements. Compare the amount payable for the actual transaction, with each inclusion stated clearly.

For a four-carat loose stone, ask whether the quoted amount includes the report, delivery and insurance, and how taxes or destination charges will be handled. Confirm the currency, payment method and period for which the quotation remains valid. A headline amount is difficult to judge until these details are known.

A finished ring adds another set of costs. Request separate amounts for the centre diamond, setting, any additional stones and setting work. This makes it possible to understand whether a higher total comes from the diamond or the jewellery around it.

Also establish whether “4 carat” describes the centre stone or the combined weight of all diamonds in the ring. A four-carat total-weight ring may contain a smaller centre diamond, so its price cannot be compared directly with a ring containing one four-carat stone.

Begin with a small group of stones that match your preferred shape and a narrow weight range. Keep the comparison consistent, then investigate the differences that remain.

Before choosing, make sure you can answer three questions:

• What is the exact diamond? Record the report number, weight, grades and measurements.
• What explains its appearance? Review the actual stone’s video, proportions and any relevant inspection findings.
• What is the complete purchase cost? Confirm currency, taxes, delivery, payment conditions and any separate jewellery charges.

Where one quotation costs more, ask the supplier to explain the practical benefit. That could be a preferred outline, documented cutting precision, a particular appearance or purchase terms that matter to you. The decision becomes clearer when the premium has a specific purpose.

To enquire with Uniglo Diamonds, share your preferred shape, whether you require at least 4.00 carats, your budget and currency, and any colour, clarity or measurement preferences. Include the delivery destination and clarify whether the request is for a loose diamond or a complete jewellery piece.

Explore our loose lab grown diamonds and request current four-carat options. Ask for the report details and complete quotation for each shortlisted stone so you can compare its appearance and cost together.