How to Tell the Difference Between Moissanite and Diamond

Choosing between a moissanite and a diamond can be challenging, especially since both stones offer exceptional brilliance and beauty. While they may appear similar at first glance, moissanite and diamond are fundamentally different gemstones with distinct characteristics. Understanding these differences helps buyers make confident, informed decisions—whether shopping for an engagement ring, wedding jewelry, or a timeless everyday piece.

This professional guide explains moissanite vs diamond: how to tell the difference, using clear, practical comparisons based on appearance, performance, durability, value, and long-term wear.

What is a Diamond?

A diamond is a naturally occurring gemstone formed deep within the Earth over billions of years under extreme heat and pressure. Diamonds are composed of pure carbon arranged in a crystal lattice, giving them unmatched hardness and a classic, white brilliance that has symbolized love and commitment for generations.

Diamonds can be natural or lab-grown. Lab-grown diamonds have the same physical, chemical, and optical properties as natural diamonds but are created in controlled environments.

What is Moissanite?

Moissanite is a gemstone originally discovered in a meteor crater by scientist Henri Moissan. Today, all moissanite used in jewelry is lab-created. It is composed of silicon carbide and is known for its intense sparkle and fire.

Moissanite has gained popularity as an alternative to diamonds due to its durability, affordability, and bold brilliance.

Moissanite vs Diamond: How to Tell the Difference

Although moissanite and diamond can look similar, several key factors clearly separate the two.

Brilliance and Fire

One of the most noticeable differences between moissanite and diamond is how they reflect light.

Diamonds produce a balanced brilliance with white light reflections and subtle flashes of color. This refined sparkle is often described as elegant and classic.

Moissanite, on the other hand, has a higher refractive index, meaning it bends light more strongly. As a result, it displays more colorful flashes, often called a “rainbow” or “disco” effect. Some buyers love this bold sparkle, while others prefer the understated shine of a diamond.

In bright or direct lighting, this difference becomes especially noticeable.

Color Appearance

Diamonds are graded on a color scale ranging from colorless to light yellow or brown. High-quality diamonds appear icy white and crisp.

D vs F Diamond Color: A Complete Buyer’s Guide

Moissanite tends to show slight undertones, especially in larger stone sizes. Depending on lighting, it may appear faintly yellow, green, or gray. Modern premium moissanite is designed to minimize this effect, but side-by-side comparisons often reveal subtle color differences.

Hardness and Durability

Hardness plays a crucial role in everyday wear.

Diamonds rank 10 on the Mohs scale, making them the hardest natural material on Earth. This exceptional hardness means diamonds are highly resistant to scratching.

Moissanite ranks 9.25 on the Mohs scale. While slightly softer than diamond, it is still extremely durable and suitable for daily wear. In practical terms, both stones hold up well in engagement rings and fine jewelry, though diamond remains the benchmark for long-term durability.

Weight and Density

Moissanite is lighter than diamond. Two stones of the same size will not weigh the same in carats.

What is 4cs in diamonds?

Because moissanite has a lower density, it will weigh slightly less than a diamond of identical dimensions. Jewelers can often identify this difference during professional testing.

Sparkle Pattern Under Light

When viewed under certain lighting or through magnification, moissanite often displays doubled facet edges due to its double refraction property. Diamonds are singly refractive, so their facet edges appear sharp and singular.

This is one of the most reliable ways experts distinguish moissanite from diamond.

Heat and Electrical Conductivity Testing

Traditional diamond testers measure thermal conductivity. Moissanite conducts heat similarly to diamond, meaning older testers may identify both as “diamond.”

Advanced testers now measure electrical conductivity as well. Diamonds do not conduct electricity, while moissanite does. This difference allows jewelers to accurately identify each stone.

Clarity and Inclusions

Diamonds often contain natural inclusions, which are tiny internal characteristics formed during their creation. These inclusions are used to grade clarity and are unique to each stone.

Moissanite is typically created with very high clarity and fewer inclusions. While this can be appealing, the near-perfect appearance may also be a clue when comparing stones closely.

Price and Value Comparison

Price is one of the biggest differences between moissanite and diamond.

Diamonds, especially larger or higher-grade stones, command significantly higher prices due to rarity, demand, and long-standing market value.

Moissanite is far more affordable, often costing a fraction of the price of a diamond of similar size. This allows buyers to choose larger stones or more elaborate settings within the same budget.

Ethical and Environmental Considerations

Many buyers today consider sourcing and sustainability.

Lab-grown moissanite is considered an ethical option with minimal environmental impact.

Diamonds can also be ethically sourced, particularly lab-grown diamonds, which offer the same beauty and durability as natural diamonds while reducing environmental and social concerns.

Moissanite vs Diamond: Comparison Table

Feature	Diamond	Moissanite
Composition	Pure carbon	Silicon carbide
Origin	Natural or lab-grown	Lab-created
Hardness (Mohs Scale)	10 (hardest known material)	9.25 (extremely durable)
Brilliance	White, balanced sparkle	Very high sparkle with rainbow fire
Fire (Color Flashes)	Subtle and refined	Strong, colorful flashes
Refractive Index	Lower than moissanite	Higher than diamond
Color Appearance	Colorless to faint yellow (graded)	May show slight yellow, green, or gray undertones
Weight	Heavier per carat	Lighter than diamond of same size
Double Refraction	No	Yes (can show doubled facets under magnification)
Heat Conductivity	High	High (can pass basic diamond testers)
Electrical Conductivity	Does not conduct electricity	Conducts electricity
Clarity	Often contains natural inclusions	Usually eye-clean with very high clarity
Price	Premium and higher cost	Significantly more affordable
Ethical Options	Natural and lab-grown available	Lab-created and considered ethical
Best For	Traditional, timeless fine jewelry	Budget-conscious buyers who love bold sparkle

Which Should You Choose?

The choice between moissanite and diamond ultimately depends on personal preference, lifestyle, and values.

Choose a diamond if you value tradition, long-term symbolism, classic brilliance, and maximum hardness.

Choose moissanite if you prefer bold sparkle, excellent durability, and outstanding value for money.

Both gemstones are beautiful in their own way and suitable for fine jewelry, including engagement rings and wedding designs.

Final Thoughts: Moissanite vs Diamond

Understanding how to distinguish between moissanite and diamond empowers buyers to choose the gemstone that best suits their style and expectations. While diamonds offer timeless prestige and unmatched hardness, moissanite provides eye-catching brilliance and exceptional affordability.

At KRK Jewels, both moissanite and diamond jewelry are crafted with precision, transparency, and quality, ensuring every piece reflects lasting beauty and confidence, regardless of the gemstone you choose.