Caring for Soft Stones: Pearl, Coral, Opal, Turquoise, Malachite and Amber

Some of the best loved stones in Pakistan are also the softest. Moti, Marjan and Feroza have been worn for centuries, and they last well when treated with a little thought. The enemies are rarely dramatic. They are perfume, sweat, hot water, dust and the inside of a crowded drawer.

Rules for every soft stone

• Last on, first off. Put jewellery on after perfume, cream and hair spray. Take it off before washing, cooking, cleaning or exercise.
• Wipe after wear. A soft, slightly damp cloth, then a dry one. That removes sweat and oils before they settle.
• No ultrasonic or steam cleaners. These are fine for diamonds and sapphires. They can crack, dull or discolour every stone on this page.
• No harsh chemicals. Bleach, acids, ammonia and most household cleaners do harm.
• Store separately. Use soft pouches or a lined box with dividers. Dust contains quartz, which is harder than all of these stones.

Pearl (Moti)

Pearls are made of nacre, layers of calcium carbonate held together by organic material. Their hardness is only around 2.5 to 4.5.

• Acids in sweat, lemon juice, vinegar and many cosmetics slowly eat at the surface and dull the lustre.
• Store pearls flat and away from very dry heat for long periods. Nacre benefits from normal room humidity.
• Strung pearls need restringing every few years if worn often. Never hang a wet strand to dry, as the silk stretches.

Browse our pearls.

Red coral (Marjan)

Coral is the skeleton of tiny marine animals, also calcium carbonate, with hardness around 3 to 4. It is porous.

• Avoid acids and household cleaners completely. Coral reacts to them quickly.
• Heat can change colour. Ask your jeweller not to apply a torch near the stone during ring work.
• Strong sunlight over long periods may fade some coral.

See red coral.

Opal

Opal is silica with a little water locked inside. It is harder than the organics, at 5.5 to 6.5, but it can crack from knocks or sudden temperature changes.

• Do not move an opal straight from a cold air-conditioned room into hot sun, or from hot water into cold.
• Ethiopian opal is often hydrophane, meaning it can absorb water and other liquids. Keep it away from oils and soaps, and let it dry naturally if it gets wet.
• Doublets and triplets are glued and should never be soaked.

Our Australian versus Ethiopian opal guide goes deeper. See our opal collection.

Turquoise (Feroza)

Turquoise is a porous copper mineral, around 5 to 6 in hardness. Much turquoise on the market is stabilised with resin, which makes it tougher and more colour-stable.

• Oils from skin, cosmetics and cooking can be absorbed and turn sky blue towards green over years. Some people enjoy that change. Most prefer to slow it.
• Avoid soaking, including long swims and washing up.
• Heat and strong sunlight can dry and fade untreated stones.

See turquoise.

Malachite

Malachite is the banded green copper carbonate. It is around 3.5 to 4 in hardness and sensitive to acid, ammonia and heat.

• Wipe only with a damp cloth. Never soak it.
• Keep it away from household cleaners.
• Do not file, sand or polish malachite at home. Its dust should not be breathed in. Leave any repolishing to a lapidary.

Polished malachite in normal wear is fine to handle. See malachite.

Amber (Kahruba)

Amber is fossil tree resin and the softest stone here, around 2 to 2.5. It is also light and warm to the touch.

• Alcohol, perfume, nail polish remover and hair spray can leave a sticky, cloudy surface.
• Heat softens it. Never leave amber on a sunny car dashboard.
• Long exposure to light slowly darkens most amber.
• Store it alone. Almost anything will scratch it.

See amber.

Cleaning at a glance

Wearing them well

None of this means soft stones must stay in a box. They suit pendants, earrings and rings worn for occasions. If you want a daily ring, choose a bezel setting and accept that the polish may need refreshing after some years. Our ring or pendant guide explains settings in more detail.

Polish wears with time on any soft stone. A lapidary can usually restore a dull surface on coral, turquoise, malachite or amber by repolishing it lightly. Pearls cannot be repolished, which is why prevention matters most for them. Treat these stones kindly and they can be handed down for generations.