Stones That Fear Water: Which Ones Should Never Be Submerged

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Selenite, turquoise, pyrite, howlite, amber... the stones that water damages, why, and how to clean and cleanse them without getting them wet.

Key points

Soluble stones	Selenite and gypsum (about 2 g/L), ulexite, rock salt
Stones that transform	Angelite (anhydrite, becomes gypsum on contact with water)
Porous stones	Turquoise, howlite, magnesite, lapis lazuli, opal
Stones that oxidise	Pyrite, chalcopyrite, bornite, native copper
Organic materials	Amber, pearl, mother-of-pearl, coral, jet
Safe alternative	Barely damp cloth, dry brush, smoke, sound, moonlight

Why water damages some stones

Water seems harmless, and for many stones it is: a quartz or a garnet rinses without any trouble. But other materials react. Water can dissolve the stone, make it swell or change its nature, seep into its pores and carry away a dye, or encourage the oxidation of a metal or a sulphide. It can also destroy the jewellery around the stone: thread, glue, elastic, setting.

Water cleansing is a symbolic gesture, very widespread but never compulsory. Knowing which stones avoid it lets you keep the gesture without harming the stone. The chart of cleansing by stone gives the overview.

The six families of stones to keep dry

Family	Stones concerned	What happens	What to do
Soluble or transforming	Selenite, gypsum, desert rose, angelite, ulexite, rock salt	Gypsum dissolves (about 2 g per litre at 20 °C); anhydrite gradually becomes gypsum; ulexite dissolves a little, especially when hot	No water at all. Dry cloth, soft brush.
Porous or hydrated	Turquoise, howlite, magnesite, chrysocolla, opal, lapis lazuli	They absorb water, products and dyes; opal may crack as it dries	A barely damp cloth, then dry.
Oxidising	Pyrite, chalcopyrite, bornite, native copper, iron meteorites	Pyrite exposed to water and oxygen forms iron oxides and sulphuric acid; copper-bearing minerals tarnish	Keep dry, possibly with a silica gel sachet.
Organic materials	Amber, pearl, mother-of-pearl, coral, jet	Loss of lustre, cracks, thread that rots, glue that gives way	Wipe, dry at once, never let them soak.
Layered or cleavable	Lepidolite, seraphinite, fuchsite, apophyllite	Water seeps between the layers and the surface flakes	A very brief rinse if needed, then dry immediately.
Tinted or treated	Coloured agates, blue howlite, dyed quartz, treated jade, waxed lapis	The colour runs; wax or resin softens	No soaking, no hot water, no ultrasonic cleaners.

The case of selenite and angelite

Selenite is a variety of gypsum (hydrated calcium sulphate) with a hardness of 2: you can scratch it with a fingernail. Its solubility in water is about 2 grams per litre at 20 °C. That seems little, but repeated contact is enough to dull it, make it rough and lift its fibres or layers. A wand or lamp of selenite should therefore not be washed, placed in a damp saucer, or left in a bathroom.

Angelite is an anhydrite, a calcium sulphate without water, with a hardness of 3 to 3.5. It is very slightly soluble, but on contact with water it slowly takes up water and turns into gypsum, swelling as it does: this is why it is banned from concrete. On a small object the effect is slow, but it exists: it is better to avoid it.

If your selenite has taken in water, leave it to dry in the open air, away from a radiator. Some collectors then smooth the surface with very fine abrasive paper, dry, but the piece will lose its original polish.

Pyrite, hematite and metals: water that rusts

Pyrite is an iron sulphide. Exposed to oxygen and moisture, it alters into iron oxides and sulphuric acid, which explains the efflorescence and the white or yellow powders on old specimens. Most pyrite used in jewellery is stable in normal use, but a piece that often gets wet will deteriorate faster. To preserve it, keep it dry and away from bathroom humidity.

For hematite, a brief rinse is possible, but dry it thoroughly: beads sold under this name are sometimes “hematine”, a reconstituted material based on iron oxide, magnetic, which can stain or rust. Brass settings and non-stainless steel also corrode.

Dyes and mounted jewellery

A solid stone can still suffer from water if it has been dyed or stabilised with resin or wax. This is common with turquoise, lapis lazuli, howlite and magnesite dyed blue. If the water turns coloured or your cloth comes away blue, it is the dye that is running.

For bead bracelets, water weakens the elastic or silk thread, which stretches or rots. Stones glued onto a setting can come loose. Take your jewellery off before showering, washing up, swimming and going into the sea, and read how to clean a stone jewellery piece.

What to do instead?

Dust with a soft paintbrush or a soft, dry toothbrush.
Wipe with a cotton cloth that is barely damp, then at once with a dry cloth.
Blow the dust away with a rubber puffer; avoid compressed-air cans held too close.
Cleanse symbolically with smoke (at a distance), sound or moonlight.

For stones that tolerate water, use lukewarm water (never hot or icy: thermal shocks crack opal, fluorite and topaz), a little mild soap, then dry.

Frequently asked questions

Can selenite be washed in water?

No. Gypsum is soluble; water dulls it and attacks the surface. Use a dry cloth or a paintbrush.

Does turquoise tolerate water?

Not well. It is porous: water, sweat, creams and perfumes can discolour it. Take the piece off before showering and wipe it with a dry cloth.

My pyrite has white spots. Is that normal?

It is often a sign of oxidation caused by humidity. Clean it gently with a dry cloth, then store it somewhere dry, without handling it with wet hands.

Can I cleanse with sea water?

It is better to avoid it: sea water combines water and salt, two risks. It damages soft and porous stones, carbonates, metals and cords.

Is a stone that has taken in water lost?

Not always. Let it dry in the air, away from heat. A solid stone often recovers; a soluble or porous one may keep a dull or marked surface.

Also read

CareCleansing chart by stonethe stone-by-stone chart CareCleansing a stone in water: when and howcleansing in water when the stone allows it StoneSelenitethe stone most sensitive to water StoneTurquoiseporous and often treated StonePyritea sulphide that oxidises CareStones that fear salt and productsthe other major risk: salt and products

The meanings mentioned belong to tradition and symbolism. They are neither promises of results nor medical advice. Back to Care and safety for stones.

Photo: Miguel Calvo, Wikimedia Commons, CC BY 4.0

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