Moissanite for an engagement ring

An engagement ring is worn every day for decades. It gets knocked on doorframes, washed with, slept in and forgotten about. So the stone at its centre needs to be more than beautiful — it needs to stay that way. This guide looks at moissanite from that angle: why it suits a ring, how to choose the centre stone, what to talk through with your jeweller, and how to look after it. We sell the loose stone; any good jeweller can set it.

Why moissanite suits an everyday ring

Hardness

Moissanite is 9.25 on the Mohs scale. Diamond is 10 and sapphire is 9, so moissanite is harder than sapphire. In practice that means it keeps its polish and its crisp facet edges through years of wear.

Toughness

Hardness is resistance to scratching; toughness is resistance to chipping and breaking. Moissanite has no cleavage planes, so it is less prone to chipping than diamond when it takes a sharp knock.

Fire and brilliance

Moissanite's refractive index is 2.65–2.69, against diamond's 2.42, and its dispersion — the splitting of light into colour, which jewellers call fire — is 0.104, more than twice diamond's 0.044. It shows more flashes of colour than diamond, especially in sunlight. Some people love that; others prefer diamond's quieter white sparkle. The science page explains why.

Stability

Moissanite does not cloud, fade or change colour over time. If a stone looks dull, it is dirty, and a clean restores it.

Choosing the centre stone

Cut

The round brilliant is the classic and the most forgiving of wear. Ovals, pears and marquises look larger for their weight and lengthen the finger. Cushions are soft and romantic; emerald and asscher cuts are cleaner and more architectural, with broad flashes of light rather than scattered sparkle. Princess and radiant cuts give a square or rectangular outline with plenty of sparkle. We offer ten cuts, all priced by weight, so the shape you choose doesn't change the price. See every cut.

Size on a hand

Carat weight is hard to picture. Millimetres are easier: a 1.00 ct round is 6.5mm across, and a 2.00 ct round is 8mm. How big that looks depends on the hand — the same stone looks larger on a slim finger. Every stone on our site is shown at true size on a hand, calibrated to your screen with a bank card, so you can see it before you buy. Sizes are given in DEW (diamond-equivalent weight), because moissanite is a little lighter than diamond for the same size.

Grade

For a white stone, colour matters most. D, E and F are colourless. G, H and I are near-colourless, with a faint warmth that shows most in larger stones and in white metal. We sell only DEF colourless, VVS clarity, so the stone stays white whatever you set it in. The colour chart shows the scale.

Setting and metal

Claws or bezel

Claws (prongs) hold the stone at a few points and let the most light in, which shows off moissanite's fire. Four claws show more of the stone; six hold it more securely. Claws do catch on jerseys and can bend over time, so have them checked every year or so. A bezel wraps a rim of metal round the stone. It is the most protective setting and sits smoothly against clothing, at the cost of a little less light and a little less stone on show.

White or yellow metal

White gold and platinum suit a colourless stone and make it look whiter still. Yellow and rose gold give a warmer look; with a DEF stone the metal adds warmth to the setting without tinting the stone the way it would a near-colourless one. A common approach is a yellow gold band with white-metal claws holding the stone.

Popular ring styles

• Solitaire. A single stone on a plain band. Timeless, and it puts all the attention on the centre stone.
• Halo. A ring of small stones around the centre stone, which makes it look larger and adds sparkle.
• Three-stone (trilogy). A centre stone flanked by two smaller ones — often read as past, present and future. The side stones can match the centre cut or contrast with it, such as pears beside an oval.
• Pavé and side-stone bands. Small stones set along the band for extra sparkle. They need a little more care, as small stones can loosen over time.

Whichever you choose, your jeweller will want the exact millimetre size and cut of your centre stone before they start. Buy the stone first and they can design around it. Our ring size guide helps with the finger size, and designing your ring with AI is a good way to gather ideas to show them.

Caring for a moissanite ring

Moissanite needs very little. Clean it with warm water, a drop of mild dish soap and a soft toothbrush, especially behind the stone where lotion and soap collect. Rinse and dry with a soft cloth. Take the ring off for heavy work, gardening and the gym, mostly to protect the setting. Have a jeweller check the claws once a year. The stone itself will look the same in forty years as it does today.

For budgeting, see our engagement ring price guide, and for the full comparison with diamond, moissanite vs diamond.