A lab grown diamond is a real diamond: pure carbon, grown in a lab, with the same chemical, optical, and physical structure as a mined diamond. Moissanite is a different gemstone altogether, made of silicon carbide, and it is not a diamond at all. A lab grown diamond scores a perfect 10 on the Mohs hardness scale and carries an IGI or GIA diamond certificate, while moissanite scores 9.25 to 9.5 and is graded on the seller's own scale. Moissanite throws more rainbow-coloured fire because of its higher refractive index, but a lab grown diamond gives the classic white brilliance most buyers associate with a diamond. In short: choose a lab grown diamond for a certified stone with better durability and resale value, and choose moissanite for a larger, more affordable stone with extra sparkle.
What Is the Real Difference Between a Lab Grown Diamond and Moissanite?
A lab grown diamond is pure carbon, grown using HPHT or CVD technology. It is a true diamond in every sense, chemically and structurally identical to a mined one.
Moissanite is silicon carbide, a naturally occurring mineral first discovered in 1893 inside the Canyon Diablo meteor crater in Arizona by French chemist Henri Moissan (GIA). Natural moissanite is extremely rare, so almost every moissanite sold today is created in a lab. It resembles a diamond visually but is a separate gemstone with its own optical and physical properties.
Composition and Origin: Diamond Carbon vs Silicon Carbide
A lab grown diamond shares the exact atomic structure of a mined diamond, just formed in weeks instead of billions of years. This is why it carries the same GIA and IGI diamond grading reports as a natural stone.
Moissanite, being a different mineral altogether, is graded on the manufacturer's own scale, since GIA does not certify moissanite the way it certifies diamonds (Charles & Colvard).
Hardness and Durability: Which Stone Lasts Longer?
A lab grown diamond scores a perfect 10 on the Mohs hardness scale, the hardest known material, and resists scratches and chipping.
Moissanite scores 9.25 to 9.5 on the same scale, still extremely durable and suitable for daily wear in an engagement ring. In practical, everyday use, the gap between 9.25 and 10 rarely shows up as a real-world problem.
Sparkle and Brilliance: Which One Shines More?
Moissanite actually produces more visible fire than a diamond. Its refractive index sits between 2.65 and 2.69, compared to a diamond's 2.42, and this higher refraction bends light into more colourful, rainbow-style flashes.
A lab grown diamond, on the other hand, gives the classic white-light brilliance associated with traditional diamonds. Some buyers love moissanite's extra rainbow sparkle, while others prefer a diamond's more understated glow, especially in stones above 1.5 carats where the difference becomes more noticeable.
Price Comparison: Lab Grown Diamond vs Moissanite
Moissanite remains significantly cheaper than a lab grown diamond of comparable size, commonly costing a fraction of the price for similar visual impact. This gap widens further as carat size increases, since lab grown diamond prices rise faster with size while moissanite pricing stays comparatively steady.
This makes moissanite an attractive option for buyers who want a larger, eye-catching stone on a tighter budget, while a lab grown diamond suits buyers who specifically want a certified diamond, regardless of the higher cost.
Certification: How Are They Graded?
Lab grown diamonds are certified by globally recognised labs such as IGI and GIA, using the same 4Cs standard applied to natural diamonds: cut, colour, clarity, and carat. The certificate always states “laboratory-grown” clearly.
Moissanite has no universal grading authority. Most brands use their own colour and clarity scale, loosely modelled on the diamond grading system, so it helps to buy from a seller who explains their specific grading clearly.
Can You Tell the Difference Between Moissanite and a Lab Grown Diamond?
Under normal lighting and to the naked eye, most people cannot easily tell moissanite and a lab grown diamond apart. The difference becomes clearer under bright direct light or magnification, where moissanite's extra rainbow fire and double refraction stand out.
Standard diamond testers can sometimes misread moissanite as a diamond because of similar thermal conductivity. Trained gemologists rely on specialised equipment to tell the two apart accurately.
Resale Value and Long-Term Worth
Neither stone matches a natural diamond's resale value, but between the two, a lab grown diamond generally holds slightly more long-term worth, since it follows standard diamond grading and certification. Moissanite has limited resale value in the secondary market, which is worth factoring in alongside the upfront price difference.
Which One Should You Choose for an Engagement Ring in India?
Choose a lab grown diamond if you want the traditional diamond look, a certified 4Cs report, and slightly better durability and resale worth. Choose moissanite if your priority is a bigger, more affordable stone with extra sparkle and you're comfortable with a non-diamond gemstone.
Goenka Jewellers specialises in IGI-certified lab grown diamond engagement rings, with same-day delivery in Kolkata and a 100% buyback assurance, so you can compare grading and pricing with full transparency. Browse the bridal jewellery collection or check the certification FAQs to see exactly how each stone is graded before you decide.
Frequently Asked Questions
1. Is moissanite a lab grown diamond?
No. Moissanite is silicon carbide, a completely different gemstone from a diamond, even though it is also created in a lab.
2. Which is more durable, moissanite or a lab grown diamond?
A lab grown diamond is slightly harder (10 Mohs) than moissanite (9.25 to 9.5 Mohs), but both handle daily wear extremely well.
3. Why is moissanite cheaper than a lab grown diamond?
Moissanite is made of silicon carbide, which is simpler and less energy-intensive to produce than growing pure carbon into a diamond.
4. Does moissanite sparkle more than a diamond?
Yes. Moissanite has a higher refractive index, so it throws off more colourful, rainbow-style sparkle compared to a diamond's whiter brilliance.
5. Can a jeweller tell moissanite apart from a lab grown diamond?
Yes. While the two can look similar to the naked eye, a trained gemologist can distinguish them using specialised testing equipment.