Caring For Your Precious Opals

by Robert YORKE-HARDY July 18, 2021

Caring For Your Precious Opals

This blog is a brief primer on understanding your gemstones and how to enjoy them, protect them, and keep them long enough for them to become your heirloom jewellery. All gemstones need to be cared for to keep them looking there best; but, Opals are unique among gemstones and as such they should be given special attention.

Hardness and toughness
Gem and mineral hardness is measured on the MOHS scale. The scale numbers are based on the relative ease or difficulty with which one mineral can be scratched or impacted by another. But in reality, the MOHS scale is a bit deceptive. The steps of hardness between the minerals is not evenly spaced. For example, diamond at 10 is only one number away, but it’s many times harder than gems in the next category, the corundum family at 9.

Opal relative hardness is variable depending on its exact composition and formation conditions. The gems range from 5 to 6.5 on the MOHS scale. Its toughness is actually listed as "very poor to fair", making opal a gemstone that is suitable for jewellery but requires care and attention when designing jewellery and when wearing it so as to not scratch or break the stone.

Stability
Opal is generally stable, but heat from sustained exposure to intense sunlight or hot lamps can cause fracture lines called “crazing.” High heat or sudden temperature changes can also cause opal to crack or fracture.

Opal is attacked by harsh chemicals in cleaning products, hydrofluoric acid and caustic alkaline solutions.

Oil from body lotions and hand creams can be absorbed by opal which may affect the optical properties of the gemstone.

Treatments
To hide blemishes and fractures opals can be treated with oil, wax, or plastic (often with negative long term results).

To enhance color, by base color modifications to darken the base color, opal can be treated with "sugar treatment" and "smoke treatment".

Caring for Opal

Some people think that opals, rubies, diamonds and other gemstones are impervious to harm. After all, they are essentially a rock.

First and foremost, they are not common rocks...they are extremely special minerals. They are gemstones, and highly valued.

Since opals are neither a hard nor tough stone, they should be treated with care.

Some common-sense tips on opal care are:

1. Remove your opal jewellery before playing sports, gardening, household cleaning and bathing.
2. Avoid knocking or scraping the stone; protect it from scratches and blows. Remember, exposed corners can chip. When possible, chose opal jewellery where the opal is ‘bezel set’ rather than ‘claw set’.
3. Opals should never be subjected to harsh cleansers or an ultrasonic cleaning. They should also not be exposed to abrasive chemicals, acids or oils. Instead, softly rub with facial tissue or a piece of silk. Clean gently with mild detergent in room-temperature water and a soft toothbrush or cloth, and rinse to remove any residue.
Opals are often very porous; do not soak them, and never immerse a doublet or triplet. Use 99% Isopropyl alcohol(rubbing alcohol) is a good cleaning agent. It can also be used to remove oils for opal.
4. Even though opals contain water (from 3% up to 20%), they may become brittle. It’s imperative that they aren’t stored too dry or exposed to heat over a long period of time, causing them to crack and craze. With this in mind, store your opal jewellery in a padded cloth bag. For long-term storage, place the opal in cotton wool with a few drops of water and seal in a plastic bag. Keep in a dark place. Do not store in Bank safety deposit boxes which are often ‘dehumidified’ to protect paper/documents. Better yet, wear your opal jewellery.
5. Have your opal(s) and their setting inspected regularly. A professional polishing can bring new life to an opal that has become dull or has been scratched.

Caring for Opal Jewellery with diamond or other accents.

If you have accompanying diamonds with your opal jewellery, in the case of rings particularly, the diamonds can become very dull after a while, even if you’ve given the ring a clean. The main reason for this is that many people only clean the front of the ring and not the back.

So…just pour some pure, liquid wash-up detergent into the back of your ring, and scrub it from the inside with a soft toothbrush in hot water. The diamonds will sparkle again, and it will not hurt the opal as long as you don’t conduct this procedure all the time.

Check your jewellery.

It is important to inspect your jewellery regularly for claw damage. You can do this yourself if you have a magnifying glass. There’s not a mystery to it. Claws, or those little nubbin's that hold the gemstone in place on your ring or necklace.

If you can see or feel that the claw is loose or the stone moves a little, it’s good to get something done about it right away. Loose claws will cling/snag clothing. Opals are often ‘bezel set’ meaning the stone is surrounded by metal.

If you hold the item up close to your ear and rattle it, if the stone is very loose you can hear it. Be sure about it. Talk to your jeweller.

Cleaning.

Any paste or fluid designed to polish brass will also polish gold or silver. Just use a soft rag, apply the paste, and polish it off. Do not apply directly to the gemstone.

After that, once again, pour on a few drops of household detergent inside and outside, give it a scrub with a soft toothbrush and wash it off under warm water. This will bring the gold back to what it was like when you purchased the jewellery.

Also, on the subject of opal insurance…If you think your opals are insured under your household policy, make sure you have a detailed talk with your broker or agent. Ask the following questions:

How much coverage do I have for any one item; what is the minimum?
Do I need to give you a list of all my jewellery items, and the relative values?
Do you require extra money to make sure expensive items are covered?
Is my jewellery covered outside my home, while I wear it?
Am I covered if I lose any particular item or everything is covered?
What documentation do you require to file a claim?
Will you accept my purchase invoice or receipt as proof of value or do I need to get an official appraisal?
What about increased value of metals – these have risen a lot in the past few years. What would your jewellery cost to have made today? Get it appraised by a qualified gemologist. Take pictures of each piece.
How much do you suggest I insure an item for in case the replacement costs more than I paid for the original?

Giving a little forethought to your purchase and by applying the basic suggestions in this opal care blog, we are confident that you will get many years of enjoyment from your opal jewellery.

If you have any questions regarding your opal, please don’t hesitate to contact us at www.opalscanada.com and, leave a message about this blog. We will be happy to answer your questions.