What Are Lab Diamonds?
Lab-grown diamonds offer consumers a “real” diamond with the same chemical makeup, optical properties, and physical characteristics as natural diamonds. Both types are composed of carbon.
The process to create a lab-grown diamond mimics the natural diamond formation process—the only difference being that one occurs in the earth’s crust while the other takes place in a lab. To form a lab-grown diamond, extreme temperatures and pressures replicate the natural conditions that turn carbon into a diamond.
Lab-grown diamonds are evaluated using the same color, cut, carat, and clarity scales as natural diamonds, so it is essential to review this information when shopping for your stones. Grading defines the diamond’s quality.
What is Cubic Zirconia?
Similarly to lab diamonds, cubic zirconia is also a synthetically created stone; however, its crystal structure and chemical composition are entirely different. While lab-grown diamonds consist of carbon, cubic zirconia is the cubic crystalline form of zirconium dioxide, making it an affordable alternative to diamonds.
Cubic zirconia is produced by melting zirconium oxide powder with stabilizers such as magnesium and calcium at 4,982°F. Hours of heating lead to crystal formation and stabilization. These crystals are subsequently cut and polished. Each lab has its distinct methods for producing cubic zirconia.
Grading of cubic zirconia varies. They are generally colorless and internally flawless, so evaluating the cut and carat is crucial. Cubic zirconia can be graded into categories like A, AAA, and AAAAA. Grade A is of the lowest quality and is prone to damage, chipping, and tarnishing, 3A represents mid-range quality, while 5A offers the highest quality, often indistinguishable from diamonds. The top-tier 5A CZ is marketed as being hand-cut and polished.
Cubic zirconia is slightly denser than a diamond, making it heavier. Therefore, a cubic zirconia and a lab-grown diamond with the same carat weight will not be the same size—the diamond will be marginally larger.
Lab Diamonds vs Cubic Zirconia
Analyzing lab diamonds and cubic zirconia can be more straightforward by comparing them side-by-side.
| Grown Diamonds | Cubic Zirconia | |
|---|---|---|
| Chemical Composition | Carbon | ZrO2 |
| Hardness | 10 | 8.25 |
| Dispersion | 0.044 | 0.066 |
| Reflexive Index | 2.42 | 2.2 |
| Purity | All production is pure carbon | Contains zero carbon |
| Fossil Fuels Required | Negligible | Negligible |
| Water and Land Use | Negligible | Negligible |
- Availability: Both cubic zirconia and lab diamonds are highly available as they are lab-created and not mined from the earth.
- Appearance: Lab diamonds and cubic zirconia look similar but differ in sparkle, inclusion, and cut. Cubic zirconia’s brilliance is unique, and it is inclusion-free. Because CZ is less hard, its edges tend to be more rounded than diamond edges.
- Sparkle: CZ has higher dispersion (0.058 – 0.066) compared to a diamond (0.044), creating more colorful flashes under light. Lab-created diamonds exhibit brilliance through complex light reflection, giving them their coveted sparkle.
- Refraction: Cubic zirconia has a lower refractive index (2.171 – 2.177) compared to a diamond (2.417 – 2.419). This affects how light passes through it, creating different brilliance types between the two stones.
- Durability: Lab-created diamonds score a 10 on the Mohs hardness scale, whereas cubic zirconia scores between 8-8.5.
- Color: Lab-grown diamonds vary in color and are graded like natural diamonds (D – Z, from colorless to light yellow or brown). CZ is constantly colorless unless intentionally colored.
- Price: Due to different production conditions, cubic zirconia is less expensive than lab-grown diamonds.
Should You Choose CZ or Lab Diamond?
Lab diamonds are identical optically, chemically, and physically to earth-mined diamonds, making them a popular option for engagement rings.
- Durability: At 10 on the Mohs hardness scale, lab-created diamonds remain the hardest material and are as resistant to chipping as natural diamonds. Cubic zirconia scores 8-8.5 on Mohs.
- Quality: Lab-created diamonds sparkle like natural diamonds, and high-clarity stones with fewer inclusions can be more affordable.
- Ethically sourced and conflict-free: Unlike many natural diamonds, the origins of lab-grown diamonds can be traced.
- Environmentally friendly: The environmental impact is reduced with lab-created diamonds, avoiding the significant environmental and community impacts of mining.
- Cost: Lab-grown diamonds are significantly cheaper than natural diamonds, offering more value for your money.
- Availability: Both lab-grown diamonds and cubic zirconia offer numerous certified options.
- Choices: Lab-grown diamonds are available in various cuts, including pear, emerald, oval, and princess.
Consider the following tips when shopping for your jewelry:
- Lab-grown diamonds are evaluated on the same color, cut, carat, and clarity scales as natural diamonds, so review this information while shopping for stones.
- Ensure your diamond ring purchase includes a return policy and lifetime warranty.
- Online options generally offer lower prices and a broader selection.
- Ensure your lab-grown diamond is IGI certified.
In conclusion, though both lab diamonds and cubic zirconia are excellent alternatives to natural diamonds in jewelry, lab-created diamonds offer numerous additional benefits, including durability, hardness, sparkle, and certification.
