Trending
Three colourless stones, three similar-looking sparkles, three very different price tags. If you are standing in a jeweller's wondering why one ring costs a few hundred pounds and another costs several thousand, the answer is usually the stone in the middle — and the fact that only one of them is a diamond. The useful question is not which stone is "best", but which one suits your budget, how hard you are on jewellery, and how much you care about where a gem came from.
All three can look near-identical across a shop counter, so start with the basics.
Carbon crystallised under intense heat and pressure. Mined diamonds formed deep in the earth; lab-grown diamonds are made in reactors and have the same chemical composition, crystal structure and hardness as mined ones. The difference is origin, not substance. Both are graded on the familiar four Cs: cut, colour, clarity and carat weight.
Silicon carbide. Natural moissanite exists almost entirely in meteorites and is vanishingly rare in jewellery sizes, so the stones sold in shops are lab-created. It sits around 9.25 on the Mohs hardness scale — harder than most gemstones, softer than diamond.
Zirconium dioxide, made in a lab, usually at very low cost. It measures roughly 8 to 8.5 on Mohs. Fine for earrings and occasional wear, less happy in a ring you never take off.
Diamond's reputation rests on white light return — that crisp, bright return of light from a well-cut stone, with sharp contrast between bright and dark facets. Moissanite throws more coloured fire: rainbow flashes of pink, green and yellow, especially in sunlight. It is also doubly refractive, which means a jeweller with a loupe can see doubled facet edges. Some people notice a faint greenish or greyish cast in certain moissanite under LED and fluorescent lighting; others never see it.
Cubic zirconia is genuinely dazzling when new. Its problem is not how it looks on day one but how it looks after a year of daily wear, when the surface picks up fine scratches and the stone can start to look hazy rather than crisp.
One habit worth adopting: ask to take the stones to a window. Shop spotlights flatter everything. Daylight is where you will notice tint, and where moissanite's extra fire either delights you or does not.
Hardness is not toughness. Diamond is the hardest mineral, but it can still chip along its cleavage planes if knocked sharply, which is why a protective setting matters. Moissanite resists scratching extremely well and keeps its polish, but it is not indestructible — a hard knock on a thin edge can fracture it. Cubic zirconia scratches more easily and dulls over time.
Mined diamonds are regulated by the Kimberley Process, which is designed to keep conflict rough diamonds out of legitimate trade. It addresses conflict funding, not labour conditions or environmental impact, so provenance questions go further than that certificate. Lab-grown diamonds avoid mining altogether, though they use significant energy — some producers now run on renewable electricity, and it is fair to ask.
Moissanite and cubic zirconia are lab-created, so there is no mining to weigh. Manufacturing conditions and country of origin still vary, and the honest answer from most retailers is that they know the factory, not the details.
Whatever you buy, ask plainly: where was this stone grown or mined, and what paperwork comes with it? A good jeweller answers without flinching. Vague answers are information too.
Prices vary enormously with size, quality and retailer, but the broad order is consistent: mined diamond at the top, lab-grown diamond substantially below a comparable mined stone, moissanite below that, and cubic zirconia cheapest by a wide margin. At the lower end, the metal often costs more than the stone — a cubic zirconia in 18ct gold can easily cost more than a moissanite set in silver.
Resale is where expectations need managing. Jewellery is not an investment in the way people hope. Diamonds have a secondhand market, but you will generally get far less than the retail price, and lab-grown stones resell more weakly again. Moissanite and cubic zirconia have very little resale value. Buy them because you love wearing them, not because they will hold money. If value retention matters to you, a pre-owned piece or a classic design in good metal is usually the smarter route — and for anything expensive, take independent advice before committing.
Ask for the stone's specification or grading report in writing, and check whether the price includes a setting warranty and a free annual clean and inspection — many jewellers offer both, and it makes a real difference to how long a ring stays looking sharp. If you are buying online, UK consumer rules normally give you a cancellation window for distance purchases, but confirm the retailer's terms before you order rather than assuming.
Finally, be honest with yourself about the reason for the purchase. If you want a diamond, moissanite will never quite settle the question, however beautiful it is. If you want a large, bright stone and would rather spend the difference on a house deposit, moissanite is a genuinely good answer, and cubic zirconia is a perfectly respectable one for the pieces you wear least. Choose the stone that fits the life the jewellery will actually live.
Photo: tooru / Pixabay
