Which Crystals Cannot Get Wet
Somebody tells you to cleanse your crystals under running water, and for most of them that is fine. For some of them it is the last thing that ever happens to them.
The rule underneath it is hardness, measured on the Mohs scale, plus what the stone is actually made of. Anything under about 5 is soft enough that water and handling will wear it. And a few stones have chemistry that makes water a genuinely bad idea regardless of how hard they are.
Here are the ones worth knowing, and what to do instead.
JUMP TO A STONE
Halite | Lepidolite | Calcite | Chrysocolla and Malachite | Pyrite | Fluorite | Apophyllite | Hemimorphite
HALITE
Mohs 2
This one is not a warning, it is a countdown. Halite is salt. Rock salt, the same thing that is in your grinder, grown into cubes over millions of years instead of days. Run it under a tap and you will watch it go. Even a humid bathroom will round off the sharp edges over a season. Keep it dry, keep it out of the steam, and it will outlive you.
LEPIDOLITE
Mohs 2.5 to 3
Lepidolite is a mica, which means it is built in sheets, like a deck of cards pressed together. Water gets between the layers and they start to lift and flake. You can scratch it with a fingernail. Dust it with a dry brush and leave it at that.
CALCITE
Mohs 3
Calcite is the stone that taught geologists the acid test, because a drop of vinegar makes it fizz. Anything acidic eats it, and tap water is usually faintly acidic. The damage is not dramatic, it is just that the crisp faces slowly go soft and cloudy and never come back.
Peach Nailhead Calcite Cluster, Natural Red Zoned Crystal Specimen, 1.4 lb Standing Formation, $58
CHRYSOCOLLA AND MALACHITE
Mohs 2 to 4
Both are copper minerals and both are soft and porous. Water dulls the polish, and prolonged soaking can leach copper out of the stone. This is the practical reason not to make a drinking elixir with a copper mineral sitting in the glass. If you want the water method, put the stone beside the glass and not in it.
PYRITE
Mohs 6 to 6.5, and it still does not matter
Pyrite is hard enough to scratch glass, which makes people assume it is fine. It is not, and the reason is chemistry rather than hardness. Pyrite is iron sulfide, and iron plus sulfur plus moisture makes sulfuric acid. Collectors call it pyrite disease. The crystal sweats, crumbles, and takes whatever it was sitting on down with it. Dry shelf, always.
FLUORITE
Mohs 4
Fluorite is soft and it has perfect cleavage in four directions, which is a mineralogist's way of saying it is full of invisible seams waiting for an excuse. Water will not dissolve it, but it will dull that glassy surface, and a knock while it is wet is how a piece comes apart along a seam you never knew was there.
Raw Purple Fluorite Crystal Sphere Holder | Burl Wood Base | Three Brass Cups | Crystal Display, $80
APOPHYLLITE
Mohs 4.5 to 5
Apophyllite holds water inside its own structure, which is where the name comes from. Get it wet and then let it dry out too fast and the surface goes chalky and starts to flake. Those glassy points are also brittle enough to snap under a thumbnail. Handle it by the matrix, never by the crystals.
HEMIMORPHITE
Mohs 4.5 to 5
That soft blue-green botryoidal surface looks like it would love a rinse. It would not. The bubbly texture is porous, it traps water underneath, and the color goes patchy and stays that way.
WHAT TO DO INSTEAD
Every one of these can be cleansed without a drop of water. Smoke from a herb bundle or incense. A night on a windowsill under the moon. Sound, from a bell or a bowl. Or simply set it on a larger quartz cluster and leave it there overnight.
For actual dirt, a dry soft brush, the kind you would use on a camera lens. That is the whole method.
THE SHORT VERSION
If you cannot remember any of this, remember two things. Salt and water are the two things that undo minerals, so a salt water soak is the worst of both. And if a stone looks fibrous, flaky, bubbly or powdery, keep it dry.
Every piece here is one of a kind. See what is on the shelf right now