Black opal from Australian Lightning Ridge under various lights

[landscape]

It seems that there are not many people who like Opal, and there is not much discussion about Opal. I post a beautiful opal in this Thread
This 9.3ct Black Opal from Lightning Ridgeis has play-of-color on both sides.
with various color effects under sunlight, shadows and LED lights



sunlight



shadows



LED lights

 

[yssie]

What camera were these photos taken with? Phone?

 

[Bron357]

Very very nice.
Im Australian and started an opal thread a while back. There are some beautiful opal pieces owned by fellow PSers.
Australian black opal is very special, apart from its rarity, the process how opal is formed is truly a miracle of nature. It’s one of the few gemstones that’s looks totally magnificent from the moment it is unearthed.
Here are some of my pieces.
The Almond Blossom ring is Ethiopian or Welo opal. The bracelet jelly opal, the ring and pendant semi crystal opal.
@missy is the most blessed owner of the most magnificent Cartier Black Opal ring that is breathtaking.

 

[missy]

Thank you @Bron357 for your kind words.

 

[bright&shiny]

Opal is in my top 5. Your stone is absolutely gorgeous. Thank you , as always, for sharing!

 

[Mrs_Strizzle]

I love opals too! Here's mine. I would LOVE to add a black opal to my collection one day. (Vendor pic first because I never can photograph what my eye sees.)

 

[theredspinel]

I love opals too! Here's mine. I would LOVE to add a black opal to my collection one day. (Vendor pic first because I never can photograph what my eye sees.)

Hi beautiful ring! What vendor was this opal from? Edit to add: was that the only vendor pic provided?

 

[Starstruck8]

Opals are magic. My Lightning Ridge black opal.

 

[Mrs_Strizzle]

Hi beautiful ring! What vendor was this opal from? Edit to add: was that the only vendor pic provided?

Hi! It was Jim McCormick and I found it on LT. He also posts links to YouTube videos in his listings. I was in absolute love watching it glitter like a rainbow disco ball and had to have it.

 

[Starstruck8]

Australian black opal is very special, apart from its rarity, the process how opal is formed is truly a miracle of nature. It’s one of the few gemstones that’s looks totally magnificent from the moment it is unearthed.

It's true! The fire is already in the rough. "Cutting" opals is just a matter of grinding away the potch and sand to showcase the good layer. Black Opal Direct's blog has some fascinating videos: https://blackopaldirect.com/blog/ (Skip the first page.)

Bron (or anyone else), is there a generally accepted theory of how Aussie opals were formed? I haven't come across one. Sure, it involved water dissolving silica, getting into cracks, then drying out. But how exactly do we get the regular arrays of uniform sized spheres that make precious opal? It seems to be a bit of a mystery.

 

[Bron357]

It's true! The fire is already in the rough. "Cutting" opals is just a matter of grinding away the potch and sand to showcase the good layer. Black Opal Direct's blog has some fascinating videos: https://blackopaldirect.com/blog/ (Skip the first page.)

Bron (or anyone else), is there a generally accepted theory of how Aussie opals were formed? I haven't come across one. Sure, it involved water dissolving silica, getting into cracks, then drying out. But how exactly do we get the regular arrays of uniform sized spheres that make precious opal? It seems to be a bit of a mystery.

Yes, opal forms from water seeping through rock and becoming silicon infused which then “dries out” and becomes opal. The colour comes from the Silicon spheres (microscopic) which must develop undisturbed for, oh, a few million years. The largest size spheres refract light into red colour, and going in down in sphere size to blue. Different size spheres produce different colours.
And the material that appears in desirable patterns, like harlequin, those spheres have to “line up” as well so multiple the rarity x 10,000 or more.
Black opal is especially rare because the potch, which is the base the opal is formed on provides, is dark. Potch can be coloured from white, cream, through grey, to dark grey.
Black opal is graded by N. N1 is the darkest and top grade. N9 is basically a cream white.
Then you have pattern and pattern coverage. Red is the top colour but a great opal will show all the colours of the rainbow. A top opal will show colour all over its face, as the quality drops there will be sections that don’t show much or any colour.
Red is the rarest and most expensive. So an N1 black opal with a harlequin pattern showing predominantly red, expensive, very expensive.
Carat weight can be a bit misleading with Opals as they are not very dense so for the carat weight you get a lot more opal face up size than other gems. Also because it’s only the face that you see and enjoy, you need to look at mm measurements and not carat weight.

 

[icy_jade]

It seems that there are not many people who like Opal, and there is not much discussion about Opal. I post a beautiful opal in this Thread

There is a whole thread here. Many opal lovers:

Any Opal lovers out there? Show and Tell please.

I'm Australian and I love opals. Strangely though, most Aussies don't like them. It may have a lot to do with the absolutely dreadful opals some stores try to sell. I have a rather large one that came to me by good fortune. I paid $100 for it (unset) at a garage (yard) sale because the dear...

www.pricescope.com

Here are mine:

 

[theredspinel]

Hi! It was Jim McCormick and I found it on LT. He also posts links to YouTube videos in his listings. I was in absolute love watching it glitter like a rainbow disco ball and had to have it.

Thanks for your response! I know opals are hard to photograph but in the vendor pic it looked a lot darker then in your pic, it’s nice to see the vendor vs reality pic!

 

[Starstruck8]

Yes, opal forms from water seeping through rock and becoming silicon infused which then “dries out” and becomes opal. The colour comes from the Silicon spheres (microscopic) which must develop undisturbed for, oh, a few million years. The largest size spheres refract light into red colour, and going in down in sphere size to blue. Different size spheres produce different colours.
And the material that appears in desirable patterns, like harlequin, those spheres have to “line up” as well so multiple the rarity x 10,000 or more.
Black opal is especially rare because the potch, which is the base the opal is formed on provides, is dark. Potch can be coloured from white, cream, through grey, to dark grey.
Black opal is graded by N. N1 is the darkest and top grade. N9 is basically a cream white.
Then you have pattern and pattern coverage. Red is the top colour but a great opal will show all the colours of the rainbow. A top opal will show colour all over its face, as the quality drops there will be sections that don’t show much or any colour.
Red is the rarest and most expensive. So an N1 black opal with a harlequin pattern showing predominantly red, expensive, very expensive.
Carat weight can be a bit misleading with Opals as they are not very dense so for the carat weight you get a lot more opal face up size than other gems. Also because it’s only the face that you see and enjoy, you need to look at mm measurements and not carat weight.

Bron, thanks for the explanation. Lots of things still puzzle me. How exactly does the drying out process result in spheres, let alone regular arrays of uniform size spheres? What conditions lead to potch, and what to precious opal? What makes Australia the "opal-hearted country"? No doubt being flat, dry and geologically stable has something to do with it. But how does that work in detail? Net searches find a few theories, but no consensus that I can see.

 

[Garnetgirl]

This is such a coincidence for me. I just received my crystal opal from Australia yesterday. I absolutely love it. I haven’t had a chance to take any photos of it yet, but will post soon.

 

[Cinders]

This is such a coincidence for me. I just received my crystal opal from Australia yesterday. I absolutely love it. I haven’t had a chance to take any photos of it yet, but will post soon.

It's very timely for me, as well. I have asked for an opal as my Christmas gift so I'm shopping right now for a good one.

I love opals---they really are magical.

 

[Pinkmartini87]

It seems that there are not many people who like Opal, and there is not much discussion about Opal. I post a beautiful opal in this Thread
This 9.3ct Black Opal from Lightning Ridgeis has play-of-color on both sides.
with various color effects under sunlight, shadows and LED lights
sunlight



shadows



LED lights

This is so gorgeous! I would love to buy a smaller one with this type of color play for setting into a ring—may I ask the vendor where you purchased this from?

 

[jordyonbass]

Bron, thanks for the explanation. Lots of things still puzzle me. How exactly does the drying out process result in spheres, let alone regular arrays of uniform size spheres? What conditions lead to potch, and what to precious opal? What makes Australia the "opal-hearted country"? No doubt being flat, dry and geologically stable has something to do with it. But how does that work in detail? Net searches find a few theories, but no consensus that I can see.

Opal is typically found around the edges of the Great Artesian Basin, an ancient inland sea that seems to have sunk below the earth's surface many millions of years ago. This gives some clues as to what happened geologically out there to produce Opal.

As to what conditions lead to either potch or precious Opal; it's the way the silica has formed within the Opal. If it's more scattered and random then it gives potch, but when the spheres stack up more neatly and uniform they produce the colour play phenomena. This is caused by white light that enters the Opal to refract back only certain hues.

 

[bright&shiny]

Bron, thanks for the explanation. Lots of things still puzzle me. How exactly does the drying out process result in spheres, let alone regular arrays of uniform size spheres? What conditions lead to potch, and what to precious opal? What makes Australia the "opal-hearted country"? No doubt being flat, dry and geologically stable has something to do with it. But how does that work in detail? Net searches find a few theories, but no consensus that I can see.

@Starstruck8, I see @jordyonbass already replied, but I’d add that going to his YouTube site and doing a deep dive into the videos will, over time, give you quite an education into how the opal does - and doesn’t - layer up. He’s a second (or third?) generation opalist (I made that term up because he knows every aspect of the business from what I’ve seen) It’s my happy place now (thanks @jordyonbass )

@Bron357 - what a great explanation, as always.

 

[fredflintstone]

I love opals too! Here's mine. I would LOVE to add a black opal to my collection one day. (Vendor pic first because I never can photograph what my eye sees.)

Just browsing through the threads. I would think by the op's, "Vendor pic first because I never can photograph what my eye sees." The Op is saying the vendor picture looks more like the Opal than her picture, not the other way around.

As I used to photograph 1000's of Opals, while the op's picture is nice, it is typical of too much light which glares off the Opal into the camera's eye washing out the colors and hence not a true representation.

Rule #1 photographing Opal. Less light works best and the best way to get a true likeness of Opal is to turn down the light let into the camera’s lens. Then you get rid of the glare that washes the Opal's colors out.

Remember, the camera does not see like the human eye. It does not automatically adjust to let less or more light in like the human eye. You must do this manually to the camera to get the most life like pictures and videos.

If you have a feature to turn down the light let into your camera, try it. You will be amazed how much more of a likeness will be made of the Opal.

 

[Mrs_Strizzle]

Thanks @fredflintstone! I've always wondered why I simply couldn't ever get it to photograph a tiny fraction as beautiful as my eye sees it.

 

[fredflintstone]

Thanks @fredflintstone! I've always wondered why I simply couldn't ever get it to photograph a tiny fraction as beautiful as my eye sees it.

You are very welcome! Just keep practicing! It took me a long time. I had no one to tell me how to do it.

 

[jordyonbass]

Thanks @fredflintstone! I've always wondered why I simply couldn't ever get it to photograph a tiny fraction as beautiful as my eye sees it.

A good rule of thumb that I use is Crystal and White Opal want the light exposure reduced to show their colours, whereas a Black Opal or Dark Opal loves light exposure to show off it's best side.

 

[Starstruck8]

Opal is typically found around the edges of the Great Artesian Basin, an ancient inland sea that seems to have sunk below the earth's surface many millions of years ago. This gives some clues as to what happened geologically out there to produce Opal.

As to what conditions lead to either potch or precious Opal; it's the way the silica has formed within the Opal. If it's more scattered and random then it gives potch, but when the spheres stack up more neatly and uniform they produce the colour play phenomena. This is caused by white light that enters the Opal to refract back only certain hues.

Jordyon, thanks for your response. I was rather hoping you would comment.

I understand the optics of light interacting with regular arrays of spheres. It's a truly wonderful thought that the fire of an opal is revealing something about its structure on scales of about 0.1-1.0 microns.

The bit I don't understand is the physics/chemistry/geology of how the silica forms into regular (or not) arrays of spheres. (Note that it doesn't always form spheres. In agates, for example, it forms strings of tiny crystals.) As far as I can tell, there seem to be two broad theories: (1) rainwater seeps down, (2) artesian water is forced up. To ignorant me, the association with the Great Artesian Basin seems to favour (2). But there seems to be no consensus. And I don't understand either theory in detail.

@Starstruck8, I see @jordyonbass already replied, but I’d add that going to his YouTube site and doing a deep dive into the videos will, over time, give you quite an education into how the opal does - and doesn’t - layer up.

Bright&shiny: thanks for the tip. I will check these out.

 

[fredflintstone]

A good rule of thumb that I use is Crystal and White Opal want the light exposure reduced to show their colours, whereas a Black Opal or Dark Opal loves light exposure to show off it's best side.

Very true, Jordy. Black Opal and darker crystal Opal are much easier to photograph and you do not want to reduce the light.

 

[jordyonbass]

Jordyon, thanks for your response. I was rather hoping you would comment.

I understand the optics of light interacting with regular arrays of spheres. It's a truly wonderful thought that the fire of an opal is revealing something about its structure on scales of about 0.1-1.0 microns.

The bit I don't understand is the physics/chemistry/geology of how the silica forms into regular (or not) arrays of spheres. (Note that it doesn't always form spheres. In agates, for example, it forms strings of tiny crystals.) As far as I can tell, there seem to be two broad theories: (1) rainwater seeps down, (2) artesian water is forced up. To ignorant me, the association with the Great Artesian Basin seems to favour (2). But there seems to be no consensus. And I don't understand either theory

Oh so the explanation as to why some Opal forms in such a neat array to create colour play?

Yeah that one has me miffed as well, but with so much colourless potch for every piece with fine gem colour - I'm going with casino luck

 

[jordyonbass]

Very true, Jordy. Black Opal and darker crystal Opal are much easier to photograph and you do not want to reduce the light.

100%, Black Opal is always a pleasure to photograph. The Black Opal in my avatar is about a B2 but on N1 body tone, it was really easy to capture compared to B3 and even some B4 crystals with a light tint.

 

[bright&shiny]

100%, Black Opal is always a pleasure to photograph. The Black Opal in my avatar is about a B2 but on N1 body tone, it was really easy to capture compared to B3 and even some B4 crystals with a light tint.

Love you avatar!

 

[Starstruck8]

Oh so the explanation as to why some Opal forms in such a neat array to create colour play?

Yeah that one has me miffed as well, but with so much colourless potch for every piece with fine gem colour - I'm going with casino luck

Yes, that's exactly what I was asking. Casino luck is pretty good story. If there really is no generally accepted theory, I'm a bit surprised. Surely people have had a long time to study it, and an incentive, because a theory would be useful in prospecting.

 

[jordyonbass]

Yes, that's exactly what I was asking. Casino luck is pretty good story. If there really is no generally accepted theory, I'm a bit surprised. Surely people have had a long time to study it, and an incentive, because a theory would be useful in prospecting.

Opals, our Galaxy, the universe, my son's toddler tantrums - why these came to be is one of the ether's secrets that we mere humans may never know.