Caring for your jewels
What is MOHS Scale?
Hardness and toughness
Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with which one mineral can be scratched by another. But the Mohs scale is deceptive. The steps between the minerals are not evenly spaced. For example, diamond is only one number away, but it’s many times harder than gems in the corundum family.
Opal hardness is variable depending on its exact composition and formation conditions, and ranges from 5 to 6.5 on the Mohs scale. Its toughness is very poor to fair, making opal a gem that is suitable for jewelry but requires care when wearing so as to not scratch or break the stone.
Stability
Opal is generally stable, but heat from intense light can cause fracture lines called “crazing.” High heat or sudden temperature changes can also cause opal to fracture. Opal is attacked by hydrofluoric acid and caustic alkaline solutions.
Cleaning
The only safe way to clean opal is with warm, soapy water.
Opal and gemstone jewellery should be handled with care to maintain its beauty. Avoid exposing opals to harsh chemicals, extreme temperatures, or sudden impacts. It's best to store opal jewellery separately from other pieces to prevent scratching. Clean opals gently with a soft cloth and avoid using harsh cleaners.
To clean the opal silver jewellery:
- Prepare a cleaning solution by mixing warm water with mild dish soap.
- Gently scrub the tarnished areas of the silver jewellery using a soft cloth or a soft-bristled toothbrush.
- Rinse the jewellery thoroughly with warm water and pat dry with a clean cloth.
- For stubborn tarnish, consider using a silver polishing cloth or a specialised silver cleaning solution, such as Silvo, and follow the manufacturer's instructions.
- Store your silver jewellery in a cool, dry place and avoid exposing it to harsh chemicals or moisture to prevent future tarnishing.
*Remember, silver will tarnish over time due to a natural chemical reaction between the silver and sulfur compounds present in the air, particularly in areas with high humidity or air pollution causing it to lose its shine and appear dull. Regular cleaning and proper storage can help minimize tarnishing and keep silver jewellery looking its best.