Certification & Quality
Every centre stone, independently graded.
Every Zurae ring is set with a lab-grown diamond graded by the International Gemological Institute. Here is what that means, the standard we hold every stone to, and how to check it for yourself.
01 · The certificate
Graded by IGI
IGI is one of the world's largest independent gem laboratories and has been grading diamonds since 1975. Its report records the 4Cs of your centre stone (cut, colour, clarity and carat) along with its exact measurements, proportions and the method used to grow it.
Your IGI report arrives in the box with your ring.
Check it yourself. Enter the report number on the IGI website to see the full grading record. Most IGI-graded diamonds also carry that number laser-inscribed on the girdle, visible under a jeweller's loupe.
Verify a report at igi.org →02 · Our standard
The 4Cs, as we choose them
Colour
E or better
Colourless. No warmth shows through, even set in yellow gold.
Clarity
VVS2 or higher
Any inclusions are extremely difficult to see, even for a trained grader at 10× magnification.
Cut
Cut for light
Excellent cut grades on round brilliants; balanced proportions and symmetry on every fancy shape.
Carat
Your choice
Every ring is made to order around the carat weight you select.
Side and accent stones: D–F colour, VS1 clarity or higher.
03 · The science
Is it a real diamond?
Yes. A lab-grown diamond is identical to a mined one in every way that can be measured. Moissanite, often sold alongside it, is a different stone altogether.
| Lab-grown | Mined | Moissanite | |
|---|---|---|---|
| Is it a diamond? | Yes | Yes | No |
| Composition | Carbon | Carbon | Silicon carbide |
| Crystal structure | Cubic | Cubic | Hexagonal |
| Hardness (Mohs) | 10 | 10 | 9.25 |
| Refractive index | 2.42 | 2.42 | 2.65 |
| Fire (dispersion) | 0.044 | 0.044 | 0.104 |
| IGI / GIA diamond grading | Yes | Yes | No |
| Origin | Lab | Mine | Lab |
| Price | $$ | $$$$ | $ |
04 · How it's grown
Two methods, one result
CVD
Chemical vapour deposition
A thin diamond seed is placed in a chamber filled with carbon-rich gas. Heated into a plasma, the gas releases carbon atoms that settle onto the seed and build the crystal layer by layer.
HPHT
High pressure, high temperature
A press recreates the crushing pressure and heat found deep inside the earth, where carbon crystallises onto a diamond seed, just as it does underground.
Either way, the result is diamond. Your IGI report states which method grew your stone.
05 · Questions
Good to know
Will a diamond tester recognise it as a diamond?
Yes. Standard diamond testers identify a lab-grown diamond as diamond, because it is one. Only specialised laboratory equipment can tell where a diamond was grown.
Will it go cloudy or change colour over time?
No. It is the same crystal as a mined diamond and will not cloud, fade or change colour. Like any diamond it picks up skin oils and lotion; a soak in warm soapy water and a soft brush bring the sparkle straight back.
Is it the same as moissanite or cubic zirconia?
No. Moissanite is silicon carbide and cubic zirconia is zirconium dioxide. Both imitate the look of a diamond but are different materials, with different hardness and a different way of handling light. A lab-grown diamond is pure carbon, and is graded by the same laboratories and the same scale as a mined diamond.
Does a lab-grown diamond hold its value?
Lab-grown diamonds are made to be worn and loved rather than bought as an investment, and their resale prices are low. We'd rather you choose a Zurae ring because you love it, and put the difference in price towards the life you're celebrating.
What comes with my ring?
Your ring arrives in a Zurae box together with the IGI report for its centre stone.