Lab Grown Marquise Diamonds

A carat is the unit used to measure a diamond's weight. One carat equals 200 milligrams or 0.2 grams. Although carat weight and the size of a diamond are related, the carat does not directly measure diamond size.

Actual Diamond Size on Size 6 Hand

Blockchain technology is revolutionizing the natural diamond industry. Our blockchain keeps track of every step in a diamond’s journey – from mining, to market, to the moment it reaches you – safely, securely, and permanently. With our blockchain-enabled diamonds, you’ll have an enduring digital record about where your diamond comes from and how it was sourced. In 2019, we became one of the first retailers to offer blockchain-enabled diamonds, and year after year we have increased our offering of blockchain-enabled diamonds, ahead of our ESG Goals.

We capture CO₂ from the atmosphere to create the most ethical lab grown diamonds on the planet. Discover the world’s largest collection of planet first lab diamonds.

Discover our collection of lab diamonds grown, cut, and polished with 100% renewable wind and solar energy.

Protect the planet with this collection of lab diamonds that are independently Sustainably Rated based on climate neutrality and investments in clean technology.

Length-to-Width Ratio –The length-to-width ratio compares the length of a diamond to its width to show how elongated a fancy-shaped diamond appears when viewed from the top. Length-to-width ratio is a matter of personal preference with some individuals preferring a more elongated shape and others a more equal or square shape. The most popular length-to-width ratios for fancy shapes are below.

Ex. A princess-cut diamond that measures 5.05 mm long by 5.00mm has a length-to-width ratio of 1.01 (5.05/5.00), and will appear perfectly square.

Most popular length-to-width ratios:
Princess: 1.00-1.05
Radiant: 1.00-1.05
Asscher: 1.00-1.05
Cushion: 1.00-1.05
Elongated Cushion: 1.20-1.49
Heart: 0.90-1.10
Emerald: 1.30-1.40
Oval: 1.30-1.70
Pear: 1.45-1.75
Marquise: 1.75-2.30

Discover Truly Brilliant ^TM- a premium collection of expertly curated diamonds chosen for their balance of traceability, sustainability, cut, color, and clarity in a variety of carat weights.

Describes the diamond's response to ultraviolet light. In diamonds with strong or very strong fluorescence, there may be some interference with the flow of light which causes a milky or oily appearance.

Describes the finish of the facets of the diamond. Polish is graded from Ideal, Excellent, Very Good, Good, Fair, or Poor. Polish grades of Good or higher have the least effect on the brilliance of the diamond and are suitable for the finest quality jewelry. Certain gem labs, such as Gemscan, incorporate Polish into an overall cut grade.

Describes the alignment of the facets of the diamond. If facets are misaligned, the diamond may poorly reflect light. Symmetry is graded from Ideal / Excellent, Very Good, Good, Fair, or Poor. Symmetry grades of Good or higher have the least effect on the brilliance of the diamond and are suitable for the finest quality jewelry. Certain gem labs, such as Gemscan, incorporate Symmetry into an overall Cut grade.

The largest facet of a gemstone, located at the top. Table % is the table width as a percentage of the girdle diameter.

The height of a gemstone, from the culet to the table. Depth % is the height of the diamond as a percentage of the girdle diameter.

Our Canadian diamonds are primarily sourced from the Diavik and Ekati mines, which are committed to high environmental and human rights standards.

Both mines have demonstrated a strong commitment to hiring local Indigenous people, providing a skilled apprenticeship program and sponsoring scholarship funds.

Brilliant Earth goes above and beyond the current industry standards to offer Beyond Conflict Free Diamonds^® with a listed origin of Botswana Sort. Botswana Sort diamonds are sourced from mines with strong social and environmental governance practices in Botswana, Namibia, South Africa, and Canada, all ranked low to moderate risk.

Our Pathway to Beyond Conflict Free™ diamonds are sourced from Angola, a country known for natural diamonds of exceptional quality. Through growing investment in sustainable practices, Angola is actively working towards more responsible mining.

Recycled diamonds have been mined, cut, and polished, were previously purchased, and are now being made available again.

Because they are repurposed after a prior purchase, these diamonds require no new mining, making them a responsible choice. This reduces the demand for new diamond mining and avoids perpetuating ongoing abuses.

An IGI-certified diamond is independently graded for quality and authenticity by the International Gemological Institute.

This certification provides a detailed assessment of a diamond’s quality based on criteria such as cut, color, clarity, and carat weight as well as ensuring authenticity.

A GIA-certified diamond is independently graded for quality and authenticity by the Gemological Institute of America.

This certification provides a detailed assessment of a diamond’s quality based on criteria such as cut, color, clarity, and carat weight as well as ensuring authenticity.

A HRD-certified diamond is graded for quality and authenticity by HRD Antwerp.

This certification assesses a diamond's quality based on its cut, color, clarity, and carat weight as well as ensures the gemstone's authenticity and quality.

A GCAL-certified diamond is graded for quality and authenticity by the Gem Certification & Assurance Lab.

This certification assesses a diamond's quality based on its cut, color, clarity, and carat weight as well as ensures the gemstone's authenticity and quality.

Hearts and Arrows diamonds are highly coveted because they’re cut with high precision and exceptional craftsmanship. These round brilliant diamonds are cut to proper proportions and crafted with a high degree of facet precision to exhibit a sharp pattern of eight arrows in the face up view and eight small hearts from the pavilion. The cut grade of hearts and arrows is evaluated by its facets appearance - exhibiting excellent face-up appearance with brightness, scintillation, and fire.

Only the rarest make the cut. Each diamond in this premium collection has the highest clarity grades*—meaning zero internal inclusions—and is hand-selected for the best ratings in color, cut, and ethical sourcing.

*A flawless (FL) diamond has no inclusions or surface blemishes, and an internally flawless (IF) diamond has no internal inclusions.