Diamond vs moissanite: two of the hardest gemstones on earth, and how to choose between them

A complete guide to natural diamonds, lab-grown diamonds, and moissanite — their origins, hardness, brilliance, and what sets them apart.

The hardest gemstones you can wear every day

When it comes to durability, diamond and moissanite sit at the very top of the Mohs hardness scale — above sapphire, above ruby, above every other gemstone commonly used in jewelry. That hardness is part of what makes both stones so enduring, both literally and culturally.

Diamond scores a perfect 10 out of 10 on the Mohs scale — the hardest natural material on earth. Moissanite scores 9.25, making it the second hardest gemstone, surpassed only by diamond. Both are exceptionally resistant to scratching, chipping, and everyday wear.

For reference:

• Diamond: 10
• Moissanite: 9.25
• Sapphire / Ruby: 9
• Topaz: 8
• Quartz: 7

This means that choosing between diamond and moissanite is not a question of durability — both will last a lifetime with normal care. The real differences lie elsewhere.

Diamond: the stone that defined fine jewelry

What is a diamond?

Diamond is pure carbon, compressed under extreme heat and pressure deep within the earth's mantle over billions of years. It is the only gemstone made of a single element, and its atomic structure — a tightly bonded carbon lattice — is what gives it unmatched hardness and its distinctive optical properties.

Natural diamonds are mined primarily in Russia, Botswana, Canada, and Australia. The quality of a diamond is evaluated using the four Cs: cut, color, clarity, and carat weight. These factors determine both its beauty and its price.

The ethics of natural diamond mining

The diamond industry has faced serious scrutiny over the decades. Conflict diamonds — also called blood diamonds — have historically been used to fund armed conflicts and human rights abuses in parts of Africa. Beyond human cost, diamond mining carries significant environmental impact: open-pit and underground mining operations contribute to deforestation, habitat destruction, soil erosion, and water contamination.

Worker welfare in mining communities has also been a persistent concern, with many operations historically marked by hazardous conditions and insufficient wages.

In response, the industry established the Kimberley Process Certification Scheme in 2003, a multilateral initiative designed to prevent conflict diamonds from entering the supply chain. While meaningful progress has been made, critics note that the Kimberley Process has limitations and that full supply chain transparency remains an ongoing challenge.

Lab-grown diamonds: the same stone, a different origin

Lab-grown diamonds — also called synthetic, lab-created, or man-made diamonds — are produced in laboratories using advanced technology that replicates the extreme heat and pressure conditions found deep within the earth. Two primary methods are used: High Pressure High Temperature (HPHT) and Chemical Vapor Deposition (CVD).

The result is a diamond that is chemically, optically, and physically identical to a mined diamond. The same carbon lattice. The same hardness of 10 Mohs. The same refractive index, the same fire, the same brilliance. Even trained gemologists cannot distinguish lab-grown from natural diamonds without specialized equipment.

Lab-grown diamonds offer two significant advantages over mined stones:

Ethics and environment — No mining means no deforestation, no habitat destruction, no conflict supply chain concerns. Lab-grown diamonds represent a verifiably responsible choice for consumers who care about where their jewelry comes from.

Accessibility — Lab-grown diamonds are typically priced significantly lower than natural diamonds of equivalent quality. This makes it possible to choose a larger stone, a better cut, or a higher color grade without a corresponding increase in cost.

At FindingYoYo, we use lab-grown diamonds — because we believe that the highest quality stone and the most responsible production method should not be in conflict with each other.

Moissanite: the gemstone born from a meteorite

What is moissanite?

Moissanite was first discovered in 1893 by French chemist Henri Moissan inside a meteorite crater in Arizona. He initially mistook the crystals for diamonds — which tells you something about how similar they appear to the naked eye. The mineral he had found was silicon carbide (SiC), and it was later named moissanite in his honor.

Natural moissanite is extraordinarily rare — found only in minute quantities in meteorites and certain geological formations. Virtually all moissanite used in jewelry today is lab-grown, produced using a process that grows silicon carbide crystals under controlled conditions. This makes moissanite one of the most sustainably produced gemstones available.

How does moissanite compare to diamond?

Moissanite and diamond look strikingly similar, but they are different materials with meaningfully different optical properties.

Hardness — Moissanite scores 9.25 on the Mohs scale, compared to diamond's 10. In practical terms, both are extremely durable and suited for everyday wear including rings. The difference is measurable but not significant for most jewelry applications.

Brilliance and fire — This is where moissanite and diamond diverge most noticeably. Diamond is renowned for its brilliance (white light reflection) and fire (colored light dispersion). Moissanite has an even higher refractive index than diamond, which means it produces more fire — more rainbow-like flashes of color, especially in direct sunlight. Some people love this; others prefer the more subdued sparkle of diamond. Neither is objectively better, but they are distinctly different.

Color — Most moissanite is produced in near-colorless (DEF equivalent) or colorless grades. High-quality lab-grown moissanite is visually very close to a top-grade diamond in everyday lighting. In certain lighting conditions, some moissanite may show a very faint yellowish or grayish tint — this is less common in premium grades.

Price — Moissanite is significantly more affordable than both natural and lab-grown diamonds of comparable size. This makes it an excellent choice for statement pieces, large center stones, or anyone who wants maximum visual impact at a more accessible price point.

Natural diamond vs lab-grown diamond vs moissanite: a clear comparison

Natural diamond

• Hardness: 10 Mohs
• Material: Carbon
• Origin: Mined from the earth
• Optical character: Classic brilliance and fire
• Price: Highest
• Ethics: Supply chain concerns; Kimberley Process provides partial protection
• Best for: Investment pieces, traditional engagement rings, heirloom jewelry

Lab-grown diamond

• Hardness: 10 Mohs
• Material: Carbon (identical to natural diamond)
• Origin: Laboratory (HPHT or CVD process)
• Optical character: Identical to natural diamond
• Price: Significantly lower than natural diamond
• Ethics: No mining, verifiably responsible production
• Best for: Consumers who want a real diamond with transparent ethics and accessible pricing

Moissanite

• Hardness: 9.25 Mohs
• Material: Silicon carbide
• Origin: Lab-grown (natural moissanite is too rare for jewelry use)
• Optical character: Higher fire than diamond; distinctive rainbow sparkle
• Price: Most accessible of the three
• Ethics: Sustainably produced, minimal environmental impact
• Best for: Those who love maximum sparkle, large statement stones, or the unique origin story

How to choose

If the word "diamond" matters to you — whether for tradition, investment, or the specific optical properties of carbon — a lab-grown diamond gives you the real thing with transparent ethics and a more accessible price point than a mined stone of equivalent quality.

If you want maximum visual impact — moissanite's higher fire means more sparkle per carat, especially in well-lit environments. If you love the way light plays in a stone, moissanite is worth serious consideration.

If you're buying an everyday piece — both lab-grown diamond and moissanite are excellent choices. With hardness scores of 10 and 9.25 respectively, both will hold up to daily wear in rings, bracelets, and pendants without special care.

If sustainability is a priority — both lab-grown diamond and moissanite are produced without mining. Lab-grown diamond uses more energy in production; moissanite's silicon carbide process is generally considered more energy-efficient. Either choice is significantly more sustainable than a mined natural diamond.

At FindingYoYo, we work with both lab-grown diamonds and moissanite, set in 925 sterling silver and gold vermeil. Our approach is simple: tell you exactly what you're getting, explain the differences honestly, and let the stone speak for itself.

Frequently asked questions

Is moissanite a fake diamond? No. Moissanite is a distinct gemstone — silicon carbide — with its own mineral identity, optical properties, and origin story. It is not a diamond substitute or imitation; it is its own material that happens to look similar and shares diamond's exceptional hardness.

Can you tell the difference between a lab-grown diamond and a natural diamond? Not with the naked eye, and not without specialized gemological equipment. Lab-grown diamonds are chemically and physically identical to natural diamonds. Even experienced jewelers cannot distinguish them visually.

Is lab-grown diamond worth buying? Yes, for most consumers. You get the same material — carbon, hardness 10, identical optical properties — at a significantly lower price, with full supply chain transparency. The main trade-off is that lab-grown diamonds do not hold their value the way rare natural diamonds can.

Which is more sparkly — diamond or moissanite? Moissanite actually has a higher refractive index than diamond, producing more fire (colored light dispersion). In direct sunlight or bright lighting, moissanite tends to show more rainbow sparkle. Diamond has a slightly more restrained, classic brilliance. Which you prefer is a matter of personal taste.

Do lab-grown diamonds and moissanite scratch easily? No. Both are among the hardest materials used in jewelry. Diamond (10 Mohs) and moissanite (9.25 Mohs) are resistant to scratching from virtually everything encountered in everyday life. Only another diamond can scratch a diamond.

What metal works best with diamond and moissanite? Both stones are colorless or near-colorless, which means metal choice significantly affects the overall look. Gold vermeil adds warmth and pairs beautifully with near-colorless stones. Sterling silver creates a cooler, more contemporary feel that lets the stone's brilliance take center stage.