Understanding Diamond Simulants: The Difference Between Real and Imitation
When shopping for brilliant fine jewelry, you will encounter many terms that sound similar but mean very different things. A simulated diamond, or diamond simulant, is one of the most important concepts to understand clearly.
Simply put, a diamond simulant is any stone that is manufactured to look like a diamond but does not share the same chemical composition or physical properties as a real diamond. They are purely imitations—they succeed in sparkle, but they are not carbon, and they are not diamonds. Understanding this fundamental difference is the first step toward making a confident jewelry purchase.
Simulants vs. Diamonds: The Fundamental Differences
The principal difference between a simulant and a real diamond (natural or lab created) is science and intrinsic value. It's not solely about its appearance; it is also about what it is and how it performs over time.
Composition and Chemical Structure
The most critical distinction is chemistry. A real diamond is composed of pure carbon crystallized in a unique isometric structure. A diamond simulant, on the other hand, is composed of completely different materials, such as zirconium dioxide (Cubic Zirconia) or silicon carbide (Moissanite). They have no chemical relation to a diamond whatsoever. If it is not pure crystallized carbon then it is a simulant.
Optical Characteristics
While simulants are created to enhance sparkle, many have observable light performance characteristics that are different from a diamond. The refractive indices of simulants differ than diamonds; therefore, light also bends differently in a simulant versus a diamond. For example, some simulants show an excessive excess of colorful fire that does not look natural and while others demonstrate the overall brilliance which is less than a true diamond. An experienced jeweler can easily identify these optical differences.
Hardness, Value, and Durability
Diamonds are the hardest known mineral (10 on the Mohs scale of hardness), and they are therefore incredibly resistant to scratching and suitable for normal wear. Simulants are much softer; for example, a Cubic Zirconia runs only 8 to 8.5. This distinction will have a direct effect on durability:
- Simulants will scratch, chip and will become cloudy or dull over time.
- A real diamond will retain its polish and brilliance indefinitely.
- Furthermore, simulants also hold virtually no resale value; however, a true diamond does.
| Feature | Diamond Simulant | Lab Grown Diamond |
|---|---|---|
| Chemical Composition | Made of different materials (e.g., Zirconium Dioxide, Silicon Carbide). Not Carbon. | Pure Crystallized Carbon |
| Atomic Structure | Different crystal structure (e.g., tetragonal, cubic). | Identical to Mined Diamond |
| Origin | Manufactured/Synthesized in a lab. | Grown in a lab (Replicates natural process). |
| Hardness (Mohs Scale) | 8.0 to 9.25 (Softer, prone to scratching/clouding). | 10 (Highest known hardness). |
| Certification | No diamond certification (only material reports). | Certified by IGI/GIA |
| Value & Longevity | Virtually None. Temporary, needs replacement. | Permanent. Designed for lifetime wear. |
Simulants vs. Lab Grown Diamonds: Clearing Up the Confusion
This could be the most significant distinction shoppers will encounter in jewelry purchases today. Terms "lab grown" and "simulant" may frequently get confused or used interchangeably when they are fundamentally different. Understanding this distinction will be important for making a high-value purchase.
Are Simulant Diamonds the Same as Lab Grown Diamonds?
Absolutely not. This is a common and often damaging misconception. A lab grown diamond is a real diamond—chemically, physically, and optically identical to a mined diamond. Both are made of pure crystallized carbon. A simulant (like Cubic Zirconia or Moissanite), however, is made of a completely different material and is merely an imitation. Only lab grown and mined diamonds are real diamonds.
Creation Process of Simulant Diamonds and Lab Diamonds
Lab grown diamonds are grown in controlled environments using high-pressure, high-temperature (HPHT) or chemical vapor deposition (CVD) processes that precisely replicate how diamonds form naturally beneath the Earth. They have the same atomic structure. Simulants, on the other hand, are simply manufactured or synthesized using processes that create entirely different crystal structures, such as silicon carbide or zirconium dioxide.
Differences in Certification and Appraisal
Because lab grown diamonds are real, they are graded and certified by the exact same independent gemological laboratories that grade mined diamonds, such as the IGI and GIA. They receive a full, authenticated report on the 4Cs. Simulants cannot be certified as diamonds because they are not carbon. While they may receive basic lab reports on their material properties, they do not receive genuine diamond certification.
Popular Diamond Simulants in Jewelry
While many materials can be used to imitate diamonds, three types dominate the market. Knowing what these simulants are made of will help you understand their inherent limitations in durability and sparkle compared to a real diamond.
Synthetic Moissanite
Naturally occurring moissanite is extremely rare, so the stones used in jewelry today are lab-created, or synthetic. Moissanite is made of silicon carbide and is often marketed as the best diamond alternative due to its high hardness (9.25 on the Mohs scale). However, moissanite is known for having a very strong, colorful fire—often described as a 'disco-ball' effect—that is noticeably and visually distinct from the subtle, nuanced sparkle of a real diamond.
Cubic Zirconia (CZ)
Cubic Zirconia is the most common and least expensive diamond simulant available. It is made from zirconium dioxide.
When a customer asks, "Is simulated diamond the same as cubic zirconia?" the answer is often yes, as CZ is the most prevalent simulant. CZ is much softer than a diamond (8–8.5 on Mohs) and is highly porous, meaning it absorbs oils and dirt quickly. This causes it to become dull or cloudy after wearing, requiring frequent cleaning and often replacement after a few years.
Other Common Diamond Simulants
Other materials are also occasionally used, though they are less frequent in high-end jewelry:
- White Sapphire: A natural gemstone used as a simulant, but it lacks the necessary brilliance and fire to truly resemble a well-cut diamond.
- Glass: Offers a very temporary, low-cost sparkle but scratches and chips almost immediately due to low hardness.
- Yttrium Aluminum Garnet (YAG): Another older lab-created simulant that has largely been replaced in popularity by CZ and Moissanite.
The Consumer View: Suitability and Longevity
When considering a diamond simulant, the main questions revolve around its performance in a real-world setting, particularly for a piece intended for daily, lifetime wear. Understanding longevity is key to a satisfied purchase.
Are Simulated Diamonds Suitable for an Engagement Ring?
While many people choose simulants for their relatively low initial cost, they are generally not recommended for high-wear jewelry like engagement rings. The reason is their basic durability. Because simulants are significantly softer than diamonds, they will inevitably show wear—including surface scratches, chips, and eventual cloudiness—within a few years of continuous wear. An engagement ring is meant to be a permanent symbol, and simulants lack the required permanence, often needing replacement to maintain their original brilliance.
Visual Inspection and Understanding Diamond Testers
For the average consumer, simple visual inspection can offer clues: a CZ may show an excessive "rainbow fire," and a Moissanite may appear noticeably double-refracted or "blurry" through the top.
Professionally, jewelers use specialized tools:
- Thermal Conductivity Testers: These tools measure how quickly heat moves through the stone. Since real diamonds are excellent heat conductors, they produce a distinct result. Most simulants (like CZ) fail this test.
- Electrical Conductivity Testers: These are necessary to differentiate between stones like Moissanite and diamond, as Moissanite also conducts heat but can be distinguished by its electrical properties.
A professional appraisal is the only way to be 100% sure of a stone's identity, especially when dealing with high-quality synthetics.
Choosing the Best Value: Why Lab Grown Diamonds?
When it comes to a piece of fine jewelry that should last a lifetime, the best value is not simply the lowest price. Rather, the best value is about the best combination of quality, ethics, and everlasting beauty. Lab grown diamonds present the best of value, as they are 100% real diamonds with the same exact physical and chemical properties as a mined diamond, except that they are made using sustainable methods.
If you want maximum sparkle, lasting brilliance, and a genuine diamond that is chemically, physically, and optically sound, lab created diamonds beat any diamond simulant. A lab grown diamond allows you to choose a larger diamond of higher quality that will retain its beauty and polish, forever.
Simulated Diamond FAQ
Are simulated diamonds real diamonds?
No, simulated diamonds are not real diamonds. A real diamond, whether mined or lab created, is composed of pure crystallized carbon. A simulated diamond is any stone—natural or manufactured—that looks like a diamond but has a different chemical structure and physical properties. They are purely imitations.
What is a diamond simulant?
A diamond simulant (also known as simulated diamond) is a stone that mimics the look of a real diamond. They are used in jewelry to provide a similar appearance and sparkle at a much lower cost. They are chemically and physically different from diamonds.
What are simulated diamonds made of?
Simulated diamonds are made from various materials, none of which is carbon. The most common materials include:
- Zirconium Dioxide: Used to make Cubic Zirconia (CZ).
- Silicon Carbide: Used to make Moissanite (which is a synthetic, or lab-created, simulant).
Is simulated diamond the same as cubic zirconia?
Not exactly, but Cubic Zirconia (CZ) is the most common and widely known type of simulated diamond. "Simulated diamond" is the broad category for any diamond imitation, while "Cubic Zirconia" is the specific material used for that imitation.
Do simulated diamonds pass a diamond tester?
Most common simulants do not pass a standard diamond tester. Standard diamond testers measure thermal conductivity (how well the stone conducts heat). Since all real diamonds—whether mined from the earth or lab grown—are excellent heat conductors, they produce a positive result. Most simulants fail this test because they are not carbon and do not conduct heat in the same way.
- Cubic Zirconia will typically fail this test.
- However, Moissanite does conduct heat well and will often pass a thermal tester. To accurately identify Moissanite, a jeweler must use a specialized electrical conductivity tester.
Is a simulated diamond worth anything?
Simulated diamonds hold virtually no investment or resale value. The value of a simulated diamond lies entirely in the initial cost of the material and the manufacturing process. Unlike real diamonds, which can retain value, simulants are priced as replaceable fashion materials and are not considered financial assets.
How long do simulated diamonds last?
Simulated diamonds do not last indefinitely. Since they are significantly softer than real diamonds:
- They are prone to scratching, chipping, and abrasion.
- Porous simulants, like CZ, can quickly absorb oils and dirt, causing them to appear cloudy or dull over time.
- Depending on the material and frequency of wear, most simulants will show noticeable deterioration within a few years of continuous use.
