Moissanite is beautiful jewelry. It has high hardness and great cost performance. But it is not a real diamond. It is not lab-grown diamond either. Moissanite is an excellent diamond simulant and alternative. However, its chemical composition and physical property are totally different from diamond.
Natural moissanite can hardly be found on Earth. The reserve is too small to support the jewelry market. For this reason, all moissanite jewelry sold today are made in lab. Its scientific name is synthetic silicon carbide, or SiC.
Moissanite is a mineral that exist in nature but extremely rare. It was first discovered by Dr. Henri Moissan, a Nobel Prize winner. That is how this stone got its name.
Moissanite VS Lab-Grown Diamond
Here is a clear chart showing their key differences.
Chemical Composition
Moissanite: Silicon Carbide (SiC)
Lab-Grown Diamond: Pure Carbon (C)
This is the biggest difference. They are two completely different substances.
Origin
Moissanite: Lab created. Natural moissanite is almost impossible to find.
Lab-Grown Diamond: Cultivated inside laboratory.
Both are man-made stones, but their materials are not the same.
Hardness (Mohs Scale)
Moissanite: 9.25
Lab-Grown Diamond: 10
Diamond is the hardest natural material in the world. Moissanite ranks second. Both are tough enough for daily wearing.
Refractive Index
Moissanite: 2.65 – 2.69
Lab-Grown Diamond: 2.42
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Moissanite has higher refractive index. It produce much stronger fire and rainbow sparkle. It looks brighter than diamond, but the strong flash may look unnatural to some people.
Dispersion
Moissanite: 0.104
Lab-Grown Diamond: 0.044
Moissanite’s dispersion is 2.5 times higher than diamond. This is why it shows such outstanding colorful fire.
Luster
Moissanite: Sub-adamantine luster
Lab-Grown Diamond: Adamantine luster
Professional jeweler can tell them apart by luster. Diamond has sharper and more brilliant shine.
Thermal & Electrical Conductivity
Moissanite: Conduct heat and electricity
Lab-Grown Diamond: Conduct heat
Common diamond tester works by checking heat conductivity. So moissanite will also show “diamond” on basic testers. But professional electric tester can tell the two apart easily.
Price
Moissanite: Much cheaper
Lab-Grown Diamond: Lower than natural diamond, but more expensive than moissanite
A high-quality 1 carat moissanite only cost tens to hundreds of currency units. A 1 carat lab-grown diamond will cost several thousand instead.
To sum up, moissanite is never a type of lab-grown diamond. It is just a high-quality diamond simulant. Lab-grown diamond is real diamond in nature. Both are lab made, but their chemicals and physical traits are fully different.
When you make a purchas, think about your budget, personal needs and how much you value authenticity. Choose the right stone that suit you best.