The round brilliant is the one shape a laboratory routinely puts a cut grade on — and this stone earned the top one. IGI report LG652452621 grades this loose one carat lab grown diamond D in color, VS 1 in clarity, and Ideal in cut, with Excellent polish and Excellent symmetry behind it. Sold loose, ready for the setting you choose.
IGI LG652452621
1.00 Carat
D Color · VS 1 Clarity
Ideal Cut Grade
Excellent Polish & Symmetry
Loose & Ready to Set
The only grade that describes the work
Color and clarity describe the material a diamond is made of. Cut describes what a human being did with it, and it is the grade that decides whether a stone looks alive across a room. On fancy shapes a report usually leaves the cut line blank and you are left judging proportions by eye. On a round brilliant it is stated outright, and here it reads Ideal — the highest cut grade on the IGI scale.
Read it alongside the two lines underneath: Excellent polish, meaning the facet surfaces carry no visible finishing marks, and Excellent symmetry, meaning the facets line up where they are supposed to. You can see that symmetry in the measurements themselves — the girdle diameters are 6.44 and 6.48 mm, four hundredths of a millimeter apart. That roundness is what keeps light returning evenly from edge to edge instead of pooling in a bright center over a lifeless rim. It is also why round engagement rings remain the benchmark everything else is measured against.
D color and VS 1 clarity, in plain terms
D is the first letter of the D-to-Z color scale and the whitest grade there is: no detectable body color at all. That matters most if you are setting the stone in yellow or rose gold, where warm metal can pull tint out of a lower color grade and put it back into the diamond. A D stone stays white against anything.
VS 1 stands for “very slightly included.” A grader working at 10x magnification can locate the inclusions; you, holding the stone at arm’s length in daylight, will not. A round brilliant is the most forgiving shape in this respect, because its crown facets break incoming light into so many directions that small inclusions have nowhere quiet to sit. Our guide to the 4Cs walks through the full scales, and the complete guide to lab grown diamonds explains how these grades are assigned.
What to set it into
A 6.44 - 6.48 mm round is the most mountable size and shape combination in fine jewelry. Nearly every setting head, every prong count, and every halo in production is built around this footprint, which means you are not limited to what a workshop happens to stock for an unusual outline. A four or six prong solitaire is the shortest route to letting the Ideal cut do its job unobstructed — see how it reads in our solitaire engagement rings.
If you want it to look larger, a hidden halo adds sparkle beneath the girdle without widening the outline you see from above. If you want it to carry meaning, a three stone setting flanks it with tapered sides. And if you already have a design in your head, our custom ring builder is where that conversation starts. Browse the rest of our loose lab grown diamonds if you are pairing stones for a set.
How this diamond was grown
The report’s comments record that this diamond was created by the High Pressure High Temperature (HPHT) growth process and classify it as Type II. It also carries the note “As Grown — no indication of post-growth treatment,” which is the line worth understanding: some lab grown diamonds are treated after growth to improve color, and this one was not. What you are looking at is what came out of the press.
It is a real diamond in every measurable sense — the same carbon lattice, the same Mohs 10 hardness, the same refractive behavior as a diamond pulled out of the ground. Because it was grown rather than mined, its origin is documented from the first day, and it is conflict-free by construction. If the distinction is new to you, start with are lab grown diamonds real diamonds and then how lab grown diamonds are made.
-
Description Laboratory grown diamond
-
Shape & cutting style Round brilliant
-
Carat weight 1.00 carat
-
Measurements 6.44 - 6.48 x 3.93 mm
-
Color grade D
-
Clarity grade VS 1
-
Cut grade Ideal
-
Polish Excellent
-
Symmetry Excellent
-
Fluorescence None
-
Growth process High Pressure High Temperature (HPHT)
-
Report comments As Grown - no indication of post-growth treatment; Type II
-
IGI report LG652452621, issued October 1, 2024
-
Inscription IGI LG652452621
-
Hardness 10 (Mohs scale)
-
Birthstone April
-
Cut style Faceted
-
Custom setting Available on request
Certification & care
The stone ships with IGI report LG652452621, issued October 1, 2024 by the International Gemological Institute. The same number is laser inscribed on the girdle as “IGI LG652452621,” readable under magnification, so the paper and the diamond stay tied to each other permanently. You can pull the report up yourself on IGI’s own report verification service by entering that number — do it before you buy if you like. If you want a third-party opinion on value as well as identity, an independent appraisal can be arranged.
At 6.44 - 6.48 x 3.93 mm the diamond is small enough to lose in a drawer and hard enough to scratch anything it is stored against, so keep it in its own compartment or the gift box it arrives in rather than loose among other jewelry. Diamond is Mohs 10 and shrugs off soap, warm water, and a soft brush; do that every few weeks once it is set and the stone will keep returning light the way the cut grade says it should. Our guide to cleaning jewelry at home covers the method in detail. Loose stones ship free within the USA, insured and tracked — details on our shipping page.
Frequently Asked Questions
What does IGI report LG652452621 cover?
It is the full grading report for this specific diamond, issued October 1, 2024. It records the description as a laboratory grown diamond, the shape and cutting style as round brilliant, measurements of 6.44 - 6.48 x 3.93 mm, a carat weight of 1.00, D color, VS 1 clarity, an Ideal cut grade, Excellent polish, Excellent symmetry, no fluorescence, the laser inscription, and comments on how the diamond was grown.
How do I verify the IGI report myself?
Take the report number, LG652452621, to the International Gemological Institute’s own online report verification service and enter it. The record IGI holds should match the document you receive line for line. Because the number is also inscribed on the stone, you can confirm that the report belongs to the diamond in your hand and not to a similar one.
What is the laser inscription on the girdle?
The girdle — the thin band around the widest part of the stone — carries “IGI LG652452621” written with a laser. It is far too small to see with the naked eye and does not affect appearance or clarity grading, but under a jeweler’s loupe or microscope it identifies this exact diamond.
Is a lab grown diamond a real diamond, and will it test as one?
Yes on both counts. A lab grown diamond is crystallized carbon with the same structure, the same Mohs 10 hardness, and the same optical properties as a mined diamond, so a standard thermal or electrical diamond tester reads it as diamond, because that is what it is. Separating grown from mined requires specialist laboratory equipment, which is exactly what IGI used to write the report.
What does a D color grade mean?
D is the top of the D-to-Z color scale: no detectable body color. It is the whitest grade a diamond can receive. The practical benefit shows up in warm metals, where yellow or rose gold can make a lower color grade look tinted; a D stone stays white regardless of what it is set in.
What does VS 1 clarity mean, and will I see the inclusions?
VS 1 means very slightly included. The inclusions are identifiable by a trained grader under 10x magnification and are not visible to the unaided eye in normal viewing. In a round brilliant they are especially hard to notice, because the faceting scatters light across the whole crown rather than leaving open windows into the stone.
Why is the Ideal cut grade the number to watch on this stone?
Because cut is the only one of the four Cs that measures craftsmanship rather than material. Proportions, angles, and finish determine how much light the diamond gathers and hands back. Ideal is the highest cut grade on IGI’s scale, and paired with Excellent polish and Excellent symmetry it means the stone is working at the top of what its color and clarity allow.
How large does a 6.46 mm round look on the hand?
That is the classic one carat footprint most people picture when they hear the phrase. Its face-up outline covers roughly 33 square millimeters. Elongated shapes of the same weight read longer on the finger, but nothing matches a round for even, all-directions sparkle at this size.
What is the difference between carat weight and millimeter size?
Carat is weight, not size — one carat is 0.2 grams. Millimeters describe the actual dimensions you see. Two one carat diamonds can look different sizes depending on how the weight is distributed, which is why this listing gives you both: 1.00 carat, measuring 6.44 - 6.48 x 3.93 mm.
Can you set this diamond into a ring for me?
Yes. This stone is sold loose and we take custom setting requests, so you can choose the design, the metal, and the karat and we will mount it. Your jeweler handles the setting work and the final band sizing, so the ring is built around both the diamond and your finger. Start from our custom ring builder or send us the design you have in mind.
Is this diamond conflict-free?
Yes. It was grown in a laboratory by the HPHT process rather than extracted from the ground, so its origin is documented from the first day of growth and there is no mining supply chain behind it.
How is a loose diamond shipped?
It ships free within the USA, fully insured and tracked, packaged securely with its IGI report and a luxury gift box. Full details are on our shipping page.
What is the return policy on a loose stone?
Loose stones follow the policy set out on our returns and refunds page. Please read it there before ordering, as the terms for a loose certified stone are not identical to those for a finished ring.
Can I have the stone appraised, and will it hold value?
An independent appraisal can be arranged and is worth having for insurance purposes. On value, we would rather be straight with you: lab grown diamonds are bought to be worn, not traded. Resale on any diamond, grown or mined, returns a fraction of retail, and lab grown prices have moved downward as production has scaled. Buy it because a D color, VS 1, Ideal cut stone costs a fraction of the mined equivalent, not as an investment.
How do I clean and care for the diamond?
Soak it in warm water with a drop of mild dish soap, brush gently with a soft toothbrush, rinse, and pat dry on a lint-free cloth. Diamond is the hardest material used in jewelry, but it will scratch other stones, so store it in its own compartment rather than loose alongside the rest of your jewelry.
