The debate between moissanite and diamond has intensified as more Australian couples consider alternatives to traditional diamond engagement rings. Both stones offer exceptional beauty and durability suitable for everyday wear, but they differ in important ways. This guide provides an honest, balanced comparison to help you make the right choice for your circumstances.
What Is Moissanite?
Moissanite (silicon carbide) was first discovered in 1893 by French chemist Henri Moissan in a meteor crater in Arizona. Natural moissanite is incredibly rare—rarer than diamonds—so virtually all moissanite used in jewellery today is lab-created. This origin story gives moissanite a unique cosmic connection that appeals to many buyers.
The laboratory creation of moissanite was perfected in the late 1990s, and the gemstone has since gained tremendous popularity as a diamond alternative. Modern moissanite is grown under controlled conditions that produce stones with consistent quality and excellent optical properties.
Brilliance and Fire: The Sparkle Factor
Both moissanite and diamond exhibit exceptional brilliance, but their optical properties differ. Moissanite has a higher refractive index (2.65-2.69) compared to diamond (2.42), meaning it bends light more dramatically. This results in more "fire"—the dispersion of light into spectral colours.
Some people absolutely love moissanite's rainbow flashes and find them more exciting than diamond's sparkle. Others prefer diamond's more balanced play of white light and fire. This is genuinely a matter of personal preference, and neither is objectively superior.
Key Difference
Moissanite's fire is often described as "disco ball" sparkle, especially in larger stones and direct sunlight. Diamond's sparkle tends to be more subtle and balanced. See both in person before deciding.
Hardness and Durability
Diamond is the hardest natural substance on Earth, rating 10 on the Mohs scale of mineral hardness. Moissanite rates 9.25, making it the second-hardest gemstone used in jewellery and harder than any other popular engagement ring stone including sapphires (9) and rubies (9).
Both stones are exceptionally durable for everyday wear. Moissanite won't scratch, chip, or break under normal conditions. It also has higher heat resistance than diamond, making it safer during jewellery repairs. For practical purposes, both stones will last a lifetime and beyond.
Cost Comparison
This is where the differences become dramatic. A high-quality 1-carat diamond typically costs between $4,000 and $12,000 AUD depending on the 4Cs. A comparable 1-carat moissanite costs between $400 and $800 AUD—roughly 10-15% of the diamond price.
This price difference allows couples to either save significantly or choose a much larger stone for the same budget. A 2-carat moissanite that would make a stunning statement ring might cost less than a modest 0.5-carat diamond.
Ethical and Environmental Considerations
Lab-created moissanite has a minimal environmental footprint compared to mined diamonds. There's no land disruption, no mining communities to consider, and no questions about conflict origins. For environmentally conscious couples, moissanite's lab-created nature is a significant advantage.
However, it's worth noting that the diamond industry has made substantial progress in ethical sourcing through the Kimberley Process, and many Australian jewellers exclusively source conflict-free diamonds. Lab-grown diamonds also offer an ethical alternative that bridges the gap between mined diamonds and moissanite.
Consider Lab-Grown Diamonds Too
Lab-grown diamonds offer the same physical and chemical properties as mined diamonds at 50-70% lower cost. They're a middle-ground option worth exploring. Read more in our Ethical Rings Guide.
Resale Value and Perception
Let's address this honestly: moissanite has virtually no resale value, while diamonds retain some percentage of their purchase price (typically 20-50% depending on quality and market conditions). If resale value matters to you, diamond is the only choice.
Social perception varies. Some people care deeply that their ring contains a "real" diamond, while others couldn't care less. There's no right answer here—it depends entirely on your values and priorities. Many couples find that the money saved on moissanite can go toward experiences, a home deposit, or the wedding itself.
Can People Tell the Difference?
In casual settings, most people cannot distinguish moissanite from diamond without specialised equipment. Even some jewellers need testing tools to be certain. The higher fire of moissanite becomes more noticeable in larger stones (above 1.5 carats) and under bright lighting conditions.
If passing as a diamond matters to you, opt for a smaller moissanite with excellent cut quality. If you're proud of choosing moissanite and happy to discuss it, size becomes less of a concern.
Making Your Decision
Choose moissanite if you prioritise value, environmental considerations, or simply love its distinctive sparkle. Choose diamond if tradition, resale value, or the symbolism of natural diamonds holds meaning for you.
Neither choice is wrong. The best engagement ring is one that aligns with your values, fits your budget, and makes you genuinely happy. We encourage you to see both stones in person—many jewellers carry both, and the hands-on comparison often makes the decision clear.
Written by Emma Richardson
Certified Gemologist
Emma is a GIA-certified gemologist with over 12 years of experience in the Australian jewellery industry. She specialises in diamond grading and has helped thousands of couples find their perfect engagement rings.