How to Care for Crystals and Gemstones Without Damaging Them

Start with hardness

The Mohs scale ranks minerals from 1 (talc) to 10 (diamond) by which one can scratch which. A stone scratches anything below it and is scratched by anything above it. Ordinary household dust contains quartz, which is 7, so anything softer than 7 slowly dulls when wiped dry with a dusty cloth.

Hardness figures come from GIA's gem encyclopedia and other gemological references. See each stone on our crystal meanings page.

A safe basic cleaning method

For most hard, untreated stones:

1. Fill a bowl with lukewarm water and add a drop of mild dish soap.
2. Clean with a soft toothbrush, paying attention to crevices.
3. Rinse in clean lukewarm water. Avoid sudden temperature changes, which can crack some stones.
4. Pat dry with a soft, lint-free cloth.

The International Gem Society recommends this kind of warm, soapy water as the safe default for most gems, and suggests checking a stone's specific needs before using ultrasonic or steam cleaners. A soft jewelry polishing cloth is handy for a quick wipe once the stone is clean and dry.

Stones that need special care

Selenite (gypsum). Very soft and slightly soluble in water. Dust it with a dry, soft brush or cloth. Never soak it, and keep it out of bathrooms.

Malachite. Soft and sensitive to acids and heat. Its dust contains copper and is harmful if breathed in or swallowed. Do not sand, cut or polish it yourself, and do not put it in water you will drink, bathe in or give to pets. Wipe with a damp cloth and dry it straight away.

Turquoise. GIA notes turquoise is porous. Skin oils, lotions, perfume and cleaning chemicals can discolor it. Put turquoise jewelry on last and take it off first. Wipe with a soft dry cloth.

Opal. Contains water, so sudden heat, very dry air or a hard knock can cause fine cracks (crazing). Clean with lukewarm water and a soft cloth. Doublets and triplets, opal slices glued to a backing, should not be soaked at all.

Pearl. Very soft and sensitive to acids, including sweat and cosmetics. Wipe with a soft damp cloth after wearing and store flat.

Emerald. Most emeralds are treated with oils or resins, so avoid ultrasonic and steam cleaners and hot water.

Lapis lazuli and hematite. Wipe clean and dry. Hematite can rust if left wet.

Sunlight and heat

Some colored stones can fade if they sit in strong sunlight for a long time. The usual suspects are amethyst, rose quartz, smoky quartz, citrine, fluorite and some colors of topaz. Light-sensitive stones do best on a shelf away from a sunny window. Heat, from a radiator, a car dashboard or a hot water rinse, can crack opal and damage treated stones.

Storing a collection

• Separate by hardness. Wrap soft stones individually, or use a box with padded compartments. A compartment storage box for crystals keeps them from rubbing together.
• Keep labels. Note the stone's name and where you got it. Many stones look alike, and labels prevent mix-ups.
• Keep dry. Store selenite, malachite, hematite and pearls away from damp rooms.
• Mind children and pets. Small tumbled stones are a choking hazard, and some minerals are harmful if swallowed.

About "cleansing" traditions

Many crystal lovers practice spiritual cleansing: leaving stones in moonlight, smudging with smoke, burying them in soil or salt, or using sound. These are traditions, not physical cleaning. Moonlight and sound will not harm a stone. Salt and soil can scratch soft stones and stain porous ones, and water can ruin selenite. If you enjoy these practices, choose ones that suit the stone.

Common questions

Can I put crystals in water?

Hard, untreated stones like clear quartz, amethyst and agate are fine in plain water for a quick rinse. Soft or porous stones such as selenite, malachite, turquoise, opal, pearl and lapis lazuli should not be soaked. Never drink water that has had stones in it.

Does sunlight harm crystals?

Long exposure to strong sunlight can fade some colored stones, including amethyst, rose quartz, smoky quartz, fluorite and some topaz. A windowsill display is the most common cause.

What about cleansing crystals with salt or moonlight?

Those are spiritual practices, not physical cleaning. Salt can scratch soft stones and damage porous ones. Moonlight is harmless. If you follow these traditions, choose methods that do not harm the stone.