Steam Cleaning
Cleaning with a jet of high-pressure steam. Fast and effective on hard stones, unsafe for pearls and soft gems.
A steamer blasts residue out of settings using pressure and heat rather than chemicals.
The thermal shock is the problem. Pearls, opals and emeralds can craze, and adhesive joints soften.
It is also the wrong tool for anything strung, since steam and heat degrade silk thread quickly.
When you are buying
For pearls the correct clean is a soft cloth lightly damped with water, followed by drying flat. Nothing else is needed and nothing else is safe.
Ultrasonic Cleaner
A tank that cleans by vibrating a liquid at high frequency. Excellent for diamonds and destructive to pearls.
Pearl Care
Pearls are soft and porous. They need to go on last, come off first, and be stored apart from everything else.
Restringing
Replacing the thread a strand is built on. Routine maintenance, not repair, and overdue on most pearl necklaces.
Opal
A hydrated silica showing shifting spectral colour, called play of colour. Soft, water-bearing and fragile.
Emerald
The green variety of beryl. Panna in Hindi, the stone of Mercury, and almost always full of internal inclusions.