FORMÉS approach to diamonds
You have decided on a diamond. What you are deciding now is which of its qualities you are paying for, and which exist only on a grading report you will file away and never open again.
The 4 Cs exist to price stones. Cut, color, clarity and carat let a laboratory describe a diamond in terms every dealer agrees on. Three of the four are graded under conditions no one wears a ring in: under magnification, against a master set of control stones, in standardized light. Whether a stone looks right on your hand is a separate question, and the grades only partly answer it.
This guide is written from our bench in Vilnius, where we select the stones we set. Our family has worked gold for over 30 years, and FORMÉS has made fine jewelry in the atelier since 2020. It gives the grades we use and shows where paying more stops showing on the hand. Where a difference is real in daily wear, we say so. Where it exists only on paper, we say that too.
Key takeaways
Grades sort stones by price. Your eye and your hand decide what is worth buying.
- Cut is the one C you read across a room, and a poor one is lost money, because it is fixed at the polishing wheel and never afterward. We set Excellent or Very Good and nothing below.
- Color F–G and clarity VS to SI1 are optimized for daily wear. The premium for the grades above them buys investment value that the eye does not register.
- Lab-grown and natural stones are both real diamonds. Buy a lab-grown stone for how it looks today and never as a store of value.
- A certificate helps only if the laser inscription matches the stone and the report is a full one.
Which is better for you, a natural or a lab-grown diamond?
Neither is more of a diamond than the other. A lab-grown stone and a mined one are the same material, and they differ in origin, environmental cost and price.
| Natural | Lab-grown | |
|---|---|---|
| How it's made | Earth-formed over 1 to 3 billion years | Created in a laboratory in 4 to 10 weeks |
| Eco impact | ~108 to 160 kg CO2 per carat | From 0.03 to 500+ kg CO2 depending on energy source |
| Why people choose it | Rarity, long-term value, timeless origin | Ethics, sustainability, more size for the budget |
| Certification | GIA, HRD, IGI, SCS-007 | GIA-LGDR, IGI, HRD, SCS-007 |
The footprint row explains why provenance matters more than the label on the box. Natural diamond production is put at roughly 108 to 160 kg of CO2 per carat. A lab-grown stone grown on clean power sits near the bottom of its range, at 0.03 kg. One grown on a coal-heavy grid sits above 500 kg, well past a mined stone.
The energy source decides it. We request full energy-source information for every diamond we offer, and we decline stones that arrive without it.
Almost nobody in the trade says this plainly: lab-grown prices have fallen steeply as the technology matured, and they are likely to keep falling. A lab diamond should be bought for the stone you receive today. That is why we price our lab stones close to cost and charge for the work: the design, the casting in recycled gold, the setting.
Our page on why we work with lab-grown diamonds sets out the sourcing in more detail. Our short Choosing Your Diamond page covers the same ground in four screens.
What do the 4 Cs mean in practice?
Cut decides what you notice first, carat gives presence, and color and clarity matter only within a band most buyers never need to leave.
Cut
Cut is the polisher's craft. The angles and proportions he cuts decide how a stone returns light, and a diamond cut too shallow or too deep leaks it through the bottom. We set only Excellent or Very Good. Below that a stone looks dull whatever its other grades say.
The GIA grades cut from Ideal to Poor, and our two accepted grades sit at the top of that scale.
Cut is also where most money is wasted. Color and clarity are fixed in the rough crystal, but a poor cut is a decision made at the wheel. Once the stone is set it is final, and no upgrade of the other three Cs repairs it. At the bench we tilt every candidate under a single lamp and watch the table. A well-cut stone keeps its light as it turns, while a poor one goes gray in patches.
Color
GIA's color scale runs from D, colorless, to Z, light yellow or brown, and every letter is a price step. We work in the D–G range, four letters out of that twenty-three.
D and E are chosen for investment. F and G give the best balance of beauty and value, since their faint warmth is invisible unless the stone sits directly beside a D or E. We have set a D and a G side by side on white card under a loupe lamp, then moved both to a finger in window light. On the card the difference reads. On the hand it disappears. Champagne, cognac and brown stones are a deliberate choice when the design calls for them.
Shape changes the advice. Emerald and Asscher cuts, both step cuts with long, open facets, show body color and inclusions far more than brilliant cuts do. For these we hold the F–G guidance tighter and look at the stone loose before anything is agreed.
Metal matters as well. A G looks whiter in white gold and warmer in 18k yellow, so we settle the metal during design rather than at grading.
Fluorescence is a further variable worth knowing. The same source notes that strong blue fluorescence can lower a diamond's value by 5–10% and sometimes gives a hazy look. We check it on the certificate before a stone is shortlisted.
Clarity
Clarity records the inclusions, the natural marks inside a stone, across 11 grades from Flawless to Included. The standard that counts is eye-clean: if you cannot see an inclusion, it does not matter.
IF to VVS mean no or almost no inclusions and are mostly bought for investment. VS and SI1 are the grades we optimize for everyday wear.
Position outweighs count. One inclusion beneath the table, the large flat top facet, is visible. Three near the girdle, the stone's outer edge, are not, because the setting's prongs and the girdle edge hide them. We read the plot on the certificate, the small diagram that maps each mark, as well as the grade, and we check the stone under 10x magnification before it goes into a mounting.
Carat
Carat is weight alone. How large a stone looks depends on its cut and on your finger. A well-cut stone of modest weight looks larger and brighter than a heavier one cut poorly.
Our ring size guide shows how to measure before you choose.
Prices step up at round weights. A 0.90 ct and a 1.00 ct look identical on the hand and do not cost the same, and the same break falls at 1.90 and 2.00 ct. Buying just under the round number is the soundest money in the decision.
How should you choose a diamond for the piece you want?
Decide what the piece is for before you choose grades, because an heirloom and an everyday ring are bought to different rules.
| Natural | Lab-grown | |
|---|---|---|
| Heirloom / investment | D–E color, IF–VVS clarity, Excellent cut, GIA or HRD certificate | D–F color, VS+ clarity, Excellent cut, GIA or IGI certificate |
| Daily wear / modern piece | F–G color, VS2–SI1 clarity, Excellent or Very Good cut | Choose what shines brightest to your eye; cut is key, color and clarity shifts cost less |
For a ring worn every day, we steer toward the second row: a strong cut, eye-clean clarity, near-colorless color, and the size you want within budget.
At the bench we look at a stone loose in tweezers, then again mounted. A diamond that looks sharp in tweezers sometimes reads differently on a finger, and we would rather learn that before the gold is cast than after. See that reasoning applied across our engagement rings.
Where should the money go in a lab-grown stone and in a natural one?
The two reward opposite spending. With lab-grown, buy the upgrades cheaply and spend the real money on cut. With natural, buy eye-clean and near-colorless, then put the rest toward size.
The reason is the price of each step. Moving from VS to VVS clarity adds around 5% in a lab-grown stone and 20% or more in a natural one. A natural VVS stone is rarer, so you pay for the rarity. A lab-grown VVS stone costs little more than a VS, and the difference is invisible on the hand either way.
In lab-grown, cut and clarity upgrades cost so little that a D–F, VS+ stone with an Excellent cut is within reach. In natural, the same money goes further on a larger F–G stone that is eye-clean.
Take a fixed budget and two rings. The lab-grown ring carries the finer grades and the better cut. The natural ring carries more carat weight at F–G and VS2 to SI1. Both are good stones. They are different purchases.
A bespoke commission begins with this budget conversation, before any stone is chosen.
What should you check on a diamond certificate?
Check three things: that the report matches the stone, that it is a full report, and that it is recent. A certificate is a grading record from an independent laboratory, and it works only if all three hold.
| Lab | Covers | What it is known for |
|---|---|---|
| GIA | Natural and lab-grown | Top-tier grading, laser-inscribed ID |
| IGI | Natural and lab-grown | Widely used in the lab-grown world |
| HRD | Natural and lab-grown | Trusted in Europe, strong on origin |
| SCS-007 | Both and recycled | Sustainability scoring, ethics guarantee |
Start with the laser inscription on the girdle. It is invisible to the eye and legible under 10x magnification, and its number must match the number on the report, because that is what ties the paper to the diamond.
Then see whether the report is a full grading report or an abbreviated one. The abbreviated version leaves out detail you will want, including the clarity plot.
Last, read the date. A report that is years old tells you less about the stone as it is now.
We work with GIA, IGI, HRD and SCS-007 across natural and lab-grown stones, and every stone from 0.30 ct upward carries an IGI, HRD or GIA report. We will read any report with you line by line before you decide.
What comes with every FORMÉS diamond?
Every diamond we set comes with the same standard, natural or lab-grown:
- Single origin: one clear journey from source to setting.
- Laser inscription, traceable to its reputable IGI, GIA or HRD certificate.
- Recycled 14K or 18K gold wherever available, responsibly mined where it is not. Cast in our atelier.
- An assay hallmark and a lifetime warranty.
Our founder and designer, Viktorija Kančinian, is a second-generation jeweler. Each piece is designed, cast and set in the family atelier in Vilnius, Lithuania.
Diamond guide FAQ
What matters more, cut or carat?
Cut. It decides how well a diamond returns light, so a smaller Excellent-cut stone outshines a larger one cut poorly. Carat only measures weight. Spend on cut first, then buy the largest well-cut stone your budget allows.
Will a lab-grown diamond hold its value?
Treat it as unlikely. Lab-grown prices have fallen as production matured and are expected to keep falling, so resale is not the reason to buy one. The reason is the stone in front of you. We price our lab-grown diamonds close to cost for exactly this reason.
Is there any visible difference between F–G and D–E color?
Not in normal wear. The faint warmth of an F or G shows only when the stone sits directly beside a D or E, which is how a grader sees it and never how a ring is worn. D and E carry a premium for rarity that exists on the report alone.
Will inclusions in a VS or SI1 stone be visible?
These grades are chosen to be eye-clean, so inclusions are not visible to the naked eye in ordinary wear. Position matters more than number. One mark beneath the table shows; several near the girdle do not. We check the plot on every certificate.
Are natural diamonds always ethical?
No. Origin and handling vary, which is why documentation matters. We use only stones with clear, certified provenance, natural or lab-grown, and we request full sourcing and energy-source information before we offer a diamond at all.
Do lab-grown diamonds test as real diamonds?
Yes. A lab-grown diamond has the same physical, chemical and optical properties as a mined one, so a standard gemological tester reads it as a diamond. Separating the two takes specialist laboratory screening, which is why the report states the origin.
Will a lab-grown diamond cloud or scratch over time?
No. A lab-grown diamond has the same hardness and durability as a natural one, so it stays clear and unmarked through normal wear. Look after it as you would any fine diamond, with warm soapy water and a soft brush.
What is the difference between a GIA and an IGI report for a lab stone?
Both are respected independent laboratories, and both grade lab-grown stones reliably. GIA is known for top-tier grading, and IGI is widely used in the lab-grown world. What matters more is that the report is a full one, that it is recent, and that its inscription matches the stone.
Can I see the stone before the piece is made?
Yes. You can view and approve the diamond before we set it, at our studio in Vilnius or online with images and the certificate. Nothing is cast until you are satisfied with the stone itself.
Do the grades choose the diamond, or only price it?
The grades tell a dealer what a stone costs. They do not tell you which one to wear. Once a diamond is well cut and eye-clean, the rest is a question of what you want to see on your hand, and most of the money above that line buys paper.
If you would like that judgment made with you, book a consultation with Viktorija, online or at our studio in Vilnius. We would rather look at a stone with you for an hour than have you choose from a chart.
Written by Viktorija Kančinian, Founder, Head of Art
Last updated October 30, 2026