Does moissanite get cloudy over time?

Updated 10 August 2026·Written by the Aqua Gold workshop, Ontario.

No — moissanite does not get cloudy over time. It is silicon carbide, a chemically inert crystal that does not react with air, water, soap or the oils in your skin. What people describe as a cloudy moissanite is almost always a thin film sitting on the surface of a stone that is, underneath, unchanged.

That distinction matters because a lot of what gets written about "cloudy" gemstones lumps every stone into one explanation, and it is not one explanation. Some gemstones genuinely change from the inside — they absorb water or chemicals, or their surface reacts with what touches it. Moissanite is not one of those. It is one of the more chemically boring materials you can set into jewellery, and here boring is the point.

Why doesn't silicon carbide cloud?

Moissanite is silicon carbide, a compound built from strong covalent bonds between silicon and carbon atoms — the same type of bond, arranged differently, that makes diamond hard. That bonding is what gives silicon carbide its two relevant properties here: it is extremely hard, at 9.25 on the Mohs scale, and it is chemically inert.

Chemically inert means the surface does not react with what it normally touches. Materials-engineering references describe sintered silicon carbide as resistant to attack at room temperature by common acids, bases and solvents — resistant enough that it is used industrially in pump seals and valve components exposed to corrosive chemicals for years. Soap, sweat, hand cream and tap water are not going to etch a surface built to withstand hydrofluoric acid.

The stone is also non-porous, unlike some gem materials covered below. There is no internal structure for moisture or chemicals to migrate into. Whatever touches moissanite stays on top of it, which is exactly why a film can build up there — and exactly why that film wipes off rather than needing to be repaired.

So what is actually causing the cloudy look?

The haze people report is a coating, not a defect in the stone. Skin naturally produces oil. Lotion, sunscreen, hand cream and soap residue all sit on top of a faceted stone the same way they sit on top of a mirror or a pair of glasses, scattering light instead of letting it pass straight through the facets.

A moissanite stone works by refracting and reflecting light very precisely off internal facet angles. A film across the top of the stone interrupts that path before the light ever gets there, so the stone looks dull or milky even though every facet underneath is cut and polished exactly as it left the workshop. Clean the film off and the optics go back to normal, because nothing about the stone changed — only what was sitting on it.

This is not unique to moissanite. Diamonds do exactly the same thing, and jewellers spend a fair amount of their day cleaning film off diamonds customers were convinced had gone "flat." Fewer people expect a diamond to cloud, so when it happens to moissanite, the stone gets blamed instead of the film.

Pieces with a continuous line of stones close together, like our moissanite tennis bracelet, pick up film fastest simply because a bracelet sits against the wrist all day, in direct contact with lotion, soap and skin oil every time you wash your hands or moisturise. That is a function of wear position, not the stone itself losing its clarity.

Which gemstones can actually cloud from within, and which can't?

"Cloudy" gets used loosely, so it helps to separate stones that genuinely change internally from stones that only pick up surface film.

Opal and pearl are the stones that genuinely earn the word cloudy. Opal is hydrated silica, and when it loses water faster than its structure can accommodate, it develops crazing — a network of fine internal cracks that a polish cannot undo. Pearl is organic and porous; perfume and cosmetic solvents can work into the nacre itself and dull it permanently. Moissanite and diamond do not have that failure mode available to them. There is no water to lose and nothing for a solvent to dissolve.

How do you clean moissanite that looks cloudy?

Warm water and a mild liquid detergent, applied with a soft-bristled brush, clears film in under a minute. Use a plain dish detergent rather than bar soap — bar soap contains fats that leave their own film behind, which defeats the point of cleaning. Work the brush behind the stone as well as across its face: prong-set pieces like our eternity band and the tennis bracelet hold stones open on the sides, so film collects underneath too, where a cloth alone cannot reach it.

Rinse thoroughly under running water before drying with a lint-free cloth — left-over detergent is itself a film. It is also worth having prongs checked once a year. That is a metalwork point rather than a stone-cleaning one, but a loose prong lets a stone move, and a moving stone chips faster than a secure one.

Does the metal or plating cloud instead of the stone?

Sometimes, and it is worth telling the two apart. Several of our pieces, including the tennis bracelet and the eternity band, are rhodium-plated 925 sterling silver. Rhodium plating is a separate metal layer over the silver, and it wears, lasts and needs renewing on its own schedule, unrelated to the moissanite set into it. If a piece looks dull at the metal rather than at the stone, cleaning the stone will not fix that — but the stone itself, moissanite, still does not cloud. Whatever else is happening on a given piece is happening to the metal, not the gem.

Which moissanite pieces show film buildup fastest?

Anything worn against skin all day and exposed to hand contact picks up film faster than anything worn once and left alone. A stud earring touches almost nothing after it goes in. A tennis bracelet or a ring is washed over, moisturised over and gripped constantly, so it is realistic to expect it to need cleaning more often — not because the stones are lower quality, but because of where they sit.

• Moissanite tennis braceleta continuous line of prong-set stones, three widths
• Moissanite eternity bandstones the whole way round, in three sizes
• Moissanite stud earringsminimal skin contact, stays clean longest
• Floating solitaire necklacea single stone in a near-invisible setting
• Marquise-cut moissanite ringworn daily, benefits from the same weekly rinse
• Moissanite cross pendantstone-set face, gold or rhodium tone
• Moissanite Miami cuban link braceletstones set along the links, two widths

You can browse the full range by category — rings, earrings, bracelets and necklaces — or start with our best sellers, which is where most people begin.

We wrote about a related myth in an earlier post, on whether moissanite passes a diamond tester: the pattern is the same one as here, where a real, checkable fact about silicon carbide gets flattened into folklore. Moissanite conducts heat well enough to read as diamond on a thermal tester, and it stays chemically stable well enough to never cloud on its own. Both are properties of the material, not sales claims about it.

Common questions

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References

The materials-science claims in this article — silicon carbide's chemical inertness toward acids, bases and solvents at room temperature, and its non-porous crystal structure — are drawn from published materials-engineering references rather than jewellery marketing copy. Opal's water content and crazing behaviour, and pearl's organic, porous composition and vulnerability to solvents, are drawn from established gemmological sources and are included here only for comparison, not as claims about our own stock.