A gemstone is a mineral highly prized for its beauty, durability, and rarity. A few noncrystalline organic materials are also classified as gemstones such as pearl, coral and amber.Gemstone hardness is based on a standard called the Mohs scale, where the higher the Mohs scale number, the harder the stone. It is important to consider this when cleaning, wearing and storing your gemstone jewellery.
The build-up of hand cream, finger prints and general dirt is common amongst your most loved jewellery, and can easily be cleaned. As a rule of thumb, gemstones at 7 and above on the Mohs scale can be cleaned with warm water, a touch of mild soap and a soft brush. For gemstones less than 7, swap the soft brush for a soft cloth.All gemstones also susceptible to damage by chemicals, water and even sunlight but prolonged exposure to the latter may cause certain gemstones to become paler. Examples include amethyst, ametrine, aquamarine, aventurine, beryl, citrine, kunzite, rose quartz and smoky quartz.Some gemstones such as opal, pearl and turquoise are fairly porous and should not be immersed in water for too long.Particular care should be taken when cleaning your emerald jewellery. A widespread practice is to treat emeralds with some form of fine oil in order to disguise the very frequent appearance of flaws. For this reason, emeralds should never be cleaned in an ultrasonic cleaning device; as such treatment will usually empty any flaws which reach the surface of the stone of any oil content, with a disastrous effect on appearance.