Moissanite is silicon carbide, not carbon. It bends light harder than a diamond does — refractive index 2.65 against 2.42 — and throws more than twice the coloured fire, at 0.104 dispersion against 0.044. On the Mohs scale it sits at 9.25, one notch below diamond and well above anything you meet in daily life.

A 2 carat D colour VVS1 moissanite costs €124.90 here. A diamond of that grade and size runs to five figures. We never describe our stones as diamonds, on any page of this shop.