Here are some tips when working with coloured gemstones:
Never put Emeralds or Tanzanite in the ultrasonic. This can remove the oil in Emeralds and the gems may fracture.
Don’t put Peridot in acid as it can etch the surface.
Beware of thermal shock which can shatter, fracture and damage gems.
Do not rinse in cold water after cleaning in a hot ultrasonic.
After heating gem set jewellery with a jewellers torch do not quench in water or acid.
Organic gems eg Pearl, Amber, Coral and Jet will burn or melt if heated and may be damaged in acid.
Be careful when using emery or filing near gems as they can be damaged by both.
Avoid repairing gem set jewellery with heat where possible. Ensure jewellery is very clean before heating as once dirt is burnt onto a gem or diamond it is impossible to remove and will ruin the beauty of the stone.
Tiny inclusions in the gem may expand and cause damage.
The gem surface may be damaged.
Certain gems including Amethyst , Citrine and Zircon may lose their colour or change colour.
Check coloured gems and diamonds are not glass fracture filled prior to heating.
For hand crafted jewellery always purchase the gem before making the setting as sometimes imagination may not match availability.
Exact calibrated sizes are not always available in coloured gems, be flexible and you will have a greater choice.