Opal - Birthstone for October

Opal - Rainbows captured in the palm of your hand!

Opal and Tourmaline are the birthstones for October.



Solid Black Australian Opal

Black Opals have a mainly dark background and are rarer than white Opals.  They are mostly found in Lightning Ridge, NSW, Australia.

Solid Australian black Opal with strong blue and green flashes, 4x3.5mm, $80.

*All these stones are available for custom orders.  Prices are included in standard designs unless marked.  I can source wonderful Australian Opals for a special custom piece for you - just get in touch.


Solid White Australian Opal

White Opals are Opals with a mainly light grey background.

Oval white Australian solid Opals, with good green, red and yellow flashes, 6x4mm.

White round solid Australian Opals, 4mm, good play of colour.

Pear shaped solid white Australian Opal, subtle sparkles of colour, 8x4mm.


5mm round white Australian Opal with good play of colour.

Solid oval white Australian Opal with mainly red flash, 8x6mm.

Solid white Australian oval Opal with excellent play of colour, 6x5mm, $105.


Opal is formed when silica solutions seep into the cracks between rocks, the water slowly evaporating over time.  In order to become precious Opal, it needs tiny spheres all same size to form that diffract the light and split it into the colours of the rainbow.  It really is a wonder of nature that the right conditions were in place to create these magical gemstones.  I especially love gemstones that create magical effects through interference and dispersion of light.

Australian Opals are the best in the world.  I took a trip to visit the town of Lighting Ridge in Outback NSW.  It was so much fun! (I didn't find any Opals though!)  Cooper Pedy in SA is also well known for it's Opal.


The most sought after Opals display the best play of colours -changing as the Opal is moved in the light, flashes of red, blue and green.  

Opals are a soft gemstone and need to be looked after carefully. Australian Opals are quite stable but Opals from other areas can dry out over time and crack.

Opals are quite soft with a hardness of 5 - 6.6, this means you need to be very careful not to scratch them.  Do not immerse in water, expose to heat or extreme temperature changes. Store them separately from other jewellery to avoid them getting scratched.


Opal Doublets

Avoid getting these wet.

Opal doublets are a thin layer of genuine Opal on a backing, often the ironstone that is found naturally with Opals.  You can usually tell by the uniform line between the top layer and back layer.  A gemstone dealer should be completely honest about what type of Opal it is, showing the different price points.  You can see examples in this article.

Large pair of blue oval Opal doublets, 18x28mm.  Beautiful waterfall like Opals, $60.

Elongated drop blue green Opal doublets pair, 31x9mm, $50.

Assorted freeform oval blue green Opal doublets, 20-30mm.

Dark blue long oval Opal doublets pair, 8x29mm, $50.


Opal triplets -Glass or clear quart top with a thin layer of Opal and other material underneath, all glued together.  Do not get these wet!

There are also many synthetic and man made Opals.  Be wary of any Opal priced too good to be true with no natural variations. (ie the colour pattern all looks the same).  If you are keen to learn more check out this article on Opal Auctions.


Boulder Opals

From Queensland

Are often thin layers of Opal veins still in the rock cracks they formed in.

Unusual blue Opal flashes in the white host rock, freeform shaped set, 32x20mm and 16x10mm, $50.

 Triangular shaped solid boulder Opal with crazed crack design, 25x15mm, $40.

Waterfall like solid Australian Boulder Opal in freeform shape, 12x8mm, $150.

**It can be hard to get a sense of scale for these gemstones, please note the dimensions and I can provide further pictures of the gemstone on my hand for size reference.  I have tried my best to represent the colours accurately but many are more vibrant in person. **


Jelly / Crystal Opal - transparent Opal

Fire Opal - transparent and Orange with no colour flashes.


Pink Opal

Opaque (not see through) and quite common compared to precious (colourful flashes) Opal.

Small faceted round pink Opal bead strands.


Find out more about Opal and how it is formed on the GIA website.

There are a few Aboriginal stories about how Opals were formed.  Read one of these stories here.


Find all the Opal designs in on my website here.















Beautiful Boulder Opal convertible silver pendant / brooch I made over 10 years ago.

Elegant simplicity Opal doublet hook earrings I made over 10 years ago.



Leave a comment

Please note, comments must be approved before they are published