Gemstones are classified by hardness up to 10 on the Mohs' scale. The most durable
gemstones for jewellery have a hardness of 7 or more. Any gemstone with a
hardness lower than 7 is easily scratched such as opal, moonstone, labradorite,
pearl, amber, turquoise, lapis, kyanite, fluorite, apatite, onyx and prehnite.
In particular, these gemstones should not be left in direct sunlight, hot or
humid conditions and should avoid getting wet, particularly the porous
stones. Emerald and kyanite are very brittle so they must not receive any
hard knocks as they are easily fractured.
Other harder gemstones such as amethyst, aquamarine, citrine, rose quartz, topaz, and
smoky quartz can fade in direct sunlight.
Other simple precautions should be taken in caring for your gemstone jewellery.
Always remove jewellery when engaging in activities that risk any knock or exposure
to chemicals, such as housework, gardening or sport. Always put on jewellery
after using any makeup, hairspray or perfumes. Wipe your jewellery
with a soft lint free cloth to remove any natural body oils. Non-porous hard
gemstones can be cleaned with lukewarm water mixed with a tiny amount of ‘Fairy Liquid’
or equivalent and gently scrubbed with a soft toothbrush. Jewellery should be stored
separately in pouches, to avoid stones coming into contact with harder materials that could
damage the surface, and to keep them away from light sources.
See also care of Precious Metals;
Pearls;
Turquoise;
Labradorite & Moonstone