Diamond Simulants vs. Lab-Grown Diamonds: What's the Difference?

Diamond alternatives are becoming more popular than ever, but not all "diamond-like" gems are the same. Two terms often confused are diamond simulants and lab-grown diamonds. While both may look similar at first glance, they are entirely different in composition, value, and long-term use.

According to a GIA report, industry analysts project that by 2025, lab-grown diamonds will account for 20% of all diamonds on the market, a clear sign of their rapidly growing acceptance. Meanwhile, simulants like cubic zirconia continue to dominate the fashion jewelry segment due to their ultra-affordable price.

In this article, we'll break down the fundamental differences between diamond simulants and lab-grown diamonds, from how they're made to how they perform in everyday wear, so that you can make the right choice for your jewelry purchase.

What Are Diamond Simulants?

Diamond simulants are gemstones that are crafted to look like diamonds but are not made of carbon and lack the same physical or chemical properties. While they can mimic the brilliance of a diamond, they fall short in terms of hardness, durability, and long-term value.

1. Common Types of Diamond Simulants

Diamond simulants come in several varieties, each with its own look, durability, and price point. While they all aim to replicate the sparkle of a real diamond, their performance and value differ greatly. The most common types include:

• Cubic Zirconia (CZ): A synthetic material made from zirconium dioxide, cubic zirconia, has been the most widely used simulant since the 1970s. It is inexpensive and readily available but significantly softer than diamonds, making it prone to scratches and dulling over time.
• Moissanite: A lab-created form of silicon carbide, moissanite is closer to diamonds in durability and sparkle. However, its rainbow-like fire and double refraction make it visually distinct from diamonds under close inspection.
• White Sapphire: A natural gemstone from the corundum family, white sapphire is durable and resistant to scratching. Its brilliance, however, is weaker compared to diamonds, giving it a softer appearance.
• Glass and Crystal: Among the least durable options, glass and crystal are highly affordable and often used in costume jewelry. They lack the hardness and brilliance that distinguish real diamonds.

2. Why People Choose Simulants

Many buyers turn to diamond simulants because they offer the beauty of a diamond at a fraction of the cost. Their affordability, wide availability, and practicality make them a popular choice for certain types of jewelry.

• Affordable Cost: Simulants are significantly less expensive than both natural and lab-grown diamonds, often costing only a fraction of the price.
• Variety and Flexibility: They are available in a wide range of cuts, colors, and sizes, making them attractive for fashion diamond jewelry or temporary use.
• Practicality: Many buyers choose simulants for travel rings, casual wear, or situations where wearing an expensive diamond might not be practical.

According to a report by Verified Market Reports, the global lab-grown gemstones market, which includes simulants like cubic zirconia and moissanite, is projected to grow steadily between 2023 and 2030 due to rising consumer demand for affordable and sustainable alternatives to natural gemstones. 

This trend highlights why diamond simulants remain popular in the fashion jewelry segment, even as lab-grown diamonds gain ground for fine jewelry.

What Are Lab-Grown Diamonds?

Lab-grown diamonds are real diamonds that are produced in controlled laboratory environments instead of being mined from the Earth. 

They share the same physical, chemical, and optical properties as natural diamonds, but are created using advanced technology.

According to Verified Market Reports, the global lab-grown gemstones market, which includes lab-grown diamonds, is projected to grow significantly between 2023 and 2030 due to rising consumer demand for sustainable and affordable luxury options.

1. How Lab-Grown Diamonds Are Created

Lab-grown diamonds are produced using two main techniques that replicate the natural diamond-growing process:

• High Pressure High Temperature (HPHT): This method mimics how diamonds form in the Earth's mantle by applying extreme heat and pressure to carbon. It produces diamonds with the same crystal structure as natural ones.
• Chemical Vapor Deposition (CVD): In this method, a thin diamond seed is placed in a carbon-rich gas chamber, where carbon atoms deposit layer by layer to grow a full diamond crystal. This process allows for high precision and consistent quality.
  

2. Why Lab-Grown Diamonds Are Real Diamonds

Lab-grown diamonds are recognized by gemological institutions worldwide as authentic diamonds because:

• Identical Composition: They are made of pure carbon in a crystal lattice, just like natural diamonds.
• Exceptional Hardness: They measure 10 on the Mohs scale, making them the hardest known material.
• Certified by Leading Institutes: Trusted organizations such as GIA and IGI grade lab-grown diamonds for cut, clarity, color, and carat weight, precisely as they do with mined diamonds.

The Gemological Institute of America confirms that lab-grown diamonds are chemically and physically indistinguishable from natural diamonds and require advanced testing instruments to tell them apart.

Key Differences Between Diamond Simulants and Lab-Grown Diamonds

While diamond simulants and lab-grown diamonds may appear similar at first glance, their differences run deep. From how they are formed to how they are certified, each category tells a very different story.

1. Composition and Origin

The first and most crucial difference lies in what they are made of.

• Simulants: Created from alternative substances like cubic zirconia, moissanite, or glass. They are designed to look like diamonds but are not composed of carbon.
• Lab-Grown: Produced from crystallized carbon, exactly like mined diamonds, making them chemically and structurally identical to natural stones.

2. Chemical Properties

Another key distinction is in their molecular structure.

• Simulants: Have completely different atomic arrangements that do not match diamond's natural crystal lattice.
• Lab-Grown: Share the exact same lattice structure as mined diamonds, meaning they exhibit identical physical and optical properties.

3. Certification and Grading

The way each type is evaluated in the gem industry highlights its differences in authenticity.           

• Simulants: Not considered genuine diamonds, so they are not graded or certified by gemological laboratories.
• Lab-Grown: Recognized as real diamonds and certified by institutes such as GIA and IGI, which assess them on the traditional diamond 4Cs: cut, clarity, color, and carat weight.

4. Appearance and Sparkle

The way a stone catches and reflects light is one of the most noticeable differences between diamond simulants and lab-grown diamonds.

• Simulants: While they can look bright at first glance, many simulants give off an overly "glassy" appearance. Stones like cubic zirconia often show rainbow-colored flashes that appear unnatural compared to a diamond's balanced brilliance. Over time, some simulants may also lose clarity and sparkle as they scratch or cloud.
• Lab-Grown: Because they are real diamonds, lab-grown stones display the same brilliance, fire, and scintillation as mined diamonds. Even under magnification, they are virtually indistinguishable from natural diamonds to the human eye, offering the same timeless sparkle.

5. Hardness and Durability

When choosing a gemstone, especially for frequently worn jewelry like engagement rings, durability matters most. The Mohs scale of mineral hardness assesses the resistance of materials to scratching. 

A higher score indicates greater durability. Diamonds, whether natural or lab-grown, consistently score a 10, making them the most scratch-resistant natural material available.

Simulants

• Cubic Zirconia (CZ): Rated 8, 8.5 on the Mohs scale. While moderately durable, CZ is significantly softer than diamonds. It can easily scratch, dull, or develop cloudy surfaces over time.
• Moissanite: Slightly tougher at 9.25. Though far more scratch-resistant than CZ, it still cannot match the exceptional hardness of genuine diamonds.

• Lab-Grown Diamonds: Lab-grown diamonds also achieve a Mohs hardness of 10, identical to mined diamonds. Their molecular composition and crystal structure give them unmatched resistance to wear, even with daily use.

Do diamond simulants last as long as real diamonds?

No. Simulants such as CZ and moissanite are softer and more prone to scratches and cloudiness. Lab-grown diamonds, by contrast, offer the same hardness and durability as natural diamonds, ensuring lasting brilliance and clarity.

Which Diamond Is Right for You?

Diamond simulants may look appealing for short-term or fashion use, but they cannot match the durability, brilliance, or value of real diamonds. Lab-grown diamonds, however, provide the same beauty and hardness as mined diamonds while being ethically sourced and more affordable.

 At Leon Diamond, we specialize in both natural and certified lab-grown diamonds, crafted with unmatched expertise since 1975. Whether you're searching for an engagement ring, wedding band, or fine jewelry, our collection ensures elegance that lasts a lifetime. Visit us to book a private appointment today to find your perfect diamond.

Frequently Asked Questions

1. Are lab-grown diamonds considered real diamonds?

Yes. Lab-grown diamonds are chemically, physically, and optically identical to mined diamonds. They are recognized and certified by gemological institutes like GIA and IGI.

2. Can lab-grown diamonds be insured like natural diamonds?

Yes. Most insurance providers cover lab-grown diamonds in the same way as mined diamonds, based on their certified value.

3. Do lab-grown diamonds come in fancy colors?

Yes. Lab-grown diamonds can be created in fancy colors like pink, blue, and yellow, often at a lower cost than rare natural colored diamonds.

4. Where can I buy certified lab-grown diamonds in New York?

You can visit Leon Diamond, where we offer both natural and GIA/IGI-certified lab-grown diamonds. Our experts provide personalized guidance in-store and online.

5. Do lab-grown diamonds require special care?

No. Lab-grown diamonds are just as durable as mined diamonds, so they require the same care, regular cleaning with mild soap, warm water, and a soft brush.