Hand sanitisers are of two types, alcohol-based and non-alcohol based. The ones containing alcohol (the chemical that kills germs) will not cause any harm to precious metals; in fact, the alcohol may dissolve some of the grime that accumulates typically between claws or adheres to gemstones. However, non-alcohol-based sanitisers usually contain a chlorine-based chemical that kills germs. These chlorine-based compounds react with water and release free chlorine radicals that are very reactive and could tarnish low carat gold and silver jewellery. Furthermore, halogens (chlorine is such a chemical) are known to cause stress corrosion cracking in low-gold items, especially in cast, mass-produced 9ct nickel white gold items.
As long as you use an alcohol-based sanitiser, your fine jewellery will be safe.
However, pearls, amber, porous gems such as turquoise and gems that have been colour-stained
should not come in contact with alcohol.
Perfumes, hairspray and sanitisers contain alcohol that will damage these gems. Their polished surfaces will lose lustre or may change colour. So, remove the jewellery set with any one of these gems before sanitising your hands and wrists. Wait five minutes for the alcohol to evaporate completely before slipping it back on your hand or wrist.
Soaps can be problematic. Some soaps contain fine abrasives (pulverised pumice rock) that will damage the surface of jewellery and even remove the thin layer of rhodium plating that covers most white gold items. These abrasive soaps will not damage your diamonds or sapphires but may leave a residue between claws or on the pavilion of a facetted gem, which will dull the sparkle. A quick wash in an ultrasonic cleaner will remove such deposits.
Most of your jewellery will be fine, but be aware of the exception described above. Please keep on sanitising while Covid-19 remains a threat.