For the Love of Gemstones

Working with gemstones can be a bit of a minefield and it helps to know a bit of background about the nature of the gemstone we are about to use.

Understanding the durability of a gemstone is tantamount to how we decide to set the stone. For example, tanzanite is an extremely fragile gem and not only should it never be put in an ultrasonic cleaner but I would be quite dubious about setting it in a ring where it will undoubtably get caught on things and be generally knocked during day to day use. At a push, if you were to set it into a ring then a rub over setting would give it the most protection but even then there are no guarantees that it will stand the test of time.

Carl Friedrich Christian Mohs, a German chemist and mineralogist developed the Moh’s scale of hardness so that we can have a better understanding of our stones (slide right to see the full table):

This was worked out on the basis that each of these ten minerals will mark or scratch a mineral with a lower number on the Moh’s scale.

However, we don’t want to test this theory by scratching our gemstones so, here is list of gemstones and what to avoid doing to them (the harness scale is courtesy of Gem-A):

(slide right to see the full table):

There aren’t many gemstones which can sustain time in the ultrasonic cleaner. Realistically, anything from an 8 and up on the Moh’s scale should be able to withstand the ultrasonic, anything lower and it will always be a risk. Remember to research the quality of your gemstone before proceeding – a heavily fractured stone of any hardness is always risky.

Let’s address the protective pastes that are sold that protect your stone if you need to solder when a stone has already been set. Do they work? The answer is, yes they do. However, they won’t protect certain stones if you have the torch near them for too long. Pearls, Amber, Opal, Emerald and any stabilised stones are unlikely to handle this. Stabilised stone are stones that have been crushed and a resin or glue has been used to put it back together.

In terms of polishing with a polishing motor, you can use it on some designs where a stone has been set, just exercise some degree of caution. The friction build up upon the piece against the polishing mop can get too hot causing your stone to crack or the colour may fade depending on what you are working with. Organic materials such as Pearl and Amber should never go near the polishing motor. Opal is another one which needs to be handled carefully. If you do need to polish around a fragile stone then it is best done by hand. You can put masking tape on the stone to protect it.

Certain gemstones don’t stand the test of time when they are not cared for. Pearls and Opals are the major culprits that spring to mind. Opals should not be put in water as they eventually lose their lovely effect and become milky. Likewise, pearls will lose their lustre over time if they are sprayed with perfume or perfumed moisturiser. You also need to be wary of household cleaning products – they will also affect your stone. It is definitely worth checking how porous your stone is. If it’s porous then it will be easily damaged.

The most porous are:

• Pearl
• Opal
• Emerald
• Amber

The best settings for the more fragile stones are a bezel/rub over setting as this will give the stone all round protection. In my humble opinion, the two stones that should ALWAYS be set in a bezel setting are Tanzanite and Opal. We see these stones set in claws all the time in jewellery shops. There is usually a cluster of diamonds or something else around the stone. This will give it some protection but not as much as a bezel setting would. Just remember there are many setting styles such as micro settings which look pretty, but the reality is they aren’t actually that practical for wear and are likely to get damaged, this will lead to customer’s returning the design for regular repair, which leads to customer frustration and reduced confidence in purchasing from you in the future.

When it comes to selling your jewellery, you should be able to give some information to your client about not just how to care for their jewellery but how to care for their gemstone too. I can’t stress to you enough how important it is to research the gemstones you purchase. Some gemstones are found in parts of the world which throw up ethical conflict. Your job as a jeweller is to source responsible materials, research your materials and make sure the designs you produce can live up to the expectation of your customer. Make sure you are educated enough on what your are supplying, to be able to educate your customer.

When you start your journey into jewellery making I think that there are definitely stones that you can practice with which are lower risk. Quartz, Jasper and Agates are great to use as they are very hard and relatively inexpensive compared to some other gems on the market but they are also attractive. Take it slow and start building your skills and then consider working with the pricy gems.