The jewellery industry has a commercial interest in you choosing a mined diamond. Keep that in mind as you read any comparison written by a retailer who only sells diamonds. This guide covers what the data actually shows.
The Core Difference
Diamond is carbon. Moissanite is silicon carbide. They are different materials with different chemical structures, different optical properties, and different price points. Moissanite is not a fake diamond or a diamond substitute. It is a distinct gemstone that happens to look similar to diamond and outperforms diamond on certain optical measures.
Brilliance
Moissanite has a refractive index of 2.65. Diamond has a refractive index of 2.42. Refractive index measures how much a material bends and returns light. A higher number means more light is returned to the eye, which means more brilliance. Moissanite is objectively more brilliant than diamond by this measure.
Moissanite also has higher dispersion than diamond, meaning it produces more coloured fire. In strong light, a moissanite produces intense rainbow flashes. A diamond produces more measured, white-light brilliance.
Which looks better is subjective. Many people prefer the intensity of moissanite. Others find it too flashy and prefer diamond's restraint. Neither is wrong.
Hardness
Diamond is 10 on the Mohs hardness scale. Moissanite is 9.25. Both are harder than any material you encounter in daily life. Scratching either stone through normal wear is essentially impossible. For practical purposes the hardness difference is irrelevant.
Appearance to Observers
Most people cannot tell the difference between a moissanite and a diamond by looking at them. A trained gemologist with specialised equipment can distinguish them. A person at a dinner table cannot. If the question is whether other people will know, the answer is no.
Price
A 1ct moissanite solitaire from our workshop costs R12,995. An equivalent 1ct mined diamond solitaire from a South African retailer costs R55,000 to R85,000. The difference is not explained by any meaningful difference in appearance, durability, or quality for everyday use. It is explained by rarity, marketing, and decades of cultural conditioning.
What the Industry Does Not Tell You
Mined diamond resale values have fallen significantly over the past five years as lab-grown diamonds have entered the mainstream market and supply has increased. The investment argument for mined diamonds, which was always overstated, is now essentially indefensible for most stone sizes.
The environmental and social concerns around diamond mining, which the industry has spent billions managing through certification schemes, do not apply to moissanite. Every moissanite is lab-grown with full supply chain transparency.
The Honest Conclusion
If having a certified diamond is important to you or your partner, choose lab-grown diamond. You get an IGI-certified diamond at 60 to 80 percent below mined diamond prices.
If maximum brilliance and the best stone for your budget is the priority, choose moissanite. You get a harder, more brilliant stone than most mined diamonds for a fraction of the price.
The only reason to choose a mined diamond in 2025 is if the specific cultural or emotional significance of a mined stone matters to you. That is a legitimate reason. It is just not an optical or practical one.