Blog Headlines: 

Opals, October birthstone

Monday, 30 December 2013  |  Anne

Opals are one of my personal favourite gemstones and they are also the birthstone for those lucky enough to be born in October. Have you looked deep into an opal? The colours change, they shimmer and shine according to how the light hits it and the type of opal it is. 


Why do opal have colour flashes?

Its the structure of opals that give the colour flashes, they are made of hydrous silica and up to 20% water . This structure splits the light with  something like little bits of a rainbow which gives the colourful effect which is so prized. Unfortunately these flashes dont easily show in photos but if you take a look at my vintage opal rings you should get some idea of what I'm talking about.


Types of opal

The opals we see in jewellery are normally white or black opals like in this fish brooch. The occasional fire opal turns up , these are more translucent and a golden amber colour.

White opals have a milky white ground and you can see flecks of red, green and blues in them depending on the exact composition of the stone

Black opals  normally have a deep blue background and you see lots of greens and flecks of red in them. Black opals remind me of peackocks in their colouring.

Fire opals are different to black and white in that they are faceted like a gemstone rather than cut and polished into cabachons. They are translucent and an orangey colour.


                                                            Opals in Jewellery

We normally see black or white opals cut as cabochons. Sometimes the opals are solid but we also see opals as doublets and triplets. A doublet is opal fused with a layer of glass either top or bottom and a triplet has glass fused both top and bottom.

There are a few reasons for this - a thinner piece of opal can be used than without the glass making the opal go further. Also if the glass is black it can then make a black opal look  darker and the flashes of colour appear brighter. The third reason is to protect the opal whilst it is being worn. This particularly applies to opal rings. Glass below the opal protects the opal from the salts in the skin and glass above the opal protects it from getting scratched.

You will often find that opals in vintage jewellery have much more colour ( Fire) than in newer pieces. Customers often remark on this once they have purchased a piece of opal jewellery from AntiquesAvenue.

Healing and mystical properties of opal

Over the years various mystical and healing properties have become associated with opals. It has been said that they amplify positive and negative emotions, they can give the wearer self confidence and protect you in a dangerous situations.

There is also a tradition that opals bring bad luck if you wear them unless your birthday is in October. Apparently this may have been started by diamond merchants who were concerned that opals were becoming more desirable than diamonds.

Care of opal jewellery.

As I mentioned earlier there is up to 20% water in opals. We must care for them in a way that protects that water as without it they loose their colour flashes or "fire" .  Opals must not be put into an ultrasonic machine nor should they be dipped into harsh chemical jewellery cleaners.

As opals are not the hardest of gemstones they are great for most pieces of jewellery but if you are wearing a ring you should take a reasonable amount of care - perhaps its best if you dont mend an engine in an opal ring or do the gardening in it. Opals can be given a gentle wash with perhaps a drop of washing up liquid. If the opals are doublets or triplets I suggest that you dont leave them to soak as the glue may come undone.

AntiquesAvenue loves opals and so you can usually find a nice selection in the shop. By the way any white opals here normally will have more colour flashed than appears in the photos as the camera just cant pick them up. This means you should be pleasantly surprised with your purchase.