❓Your Mineral Identification Questions answered here

[Heatho]

I've seen enough Aussie rubies and pink sapphs to know what they look like under UV light. :Y:

 

[Mick Cov]

Thanks goldierocks
Thats about the best I can do with the phone camera unfortunately.Im on the lookout for more now so see how we go.
The floods were the highest I have seen in maybe three winters that I have been going there and hoping for the same again this winter.
I wish I hadnt been so casual with the other one I found,I could have compared the two of them.

 

[Lefty]

I've seen enough Aussie rubies and pink sapphs to know what they look like under UV light. :Y:

All the years I've spent digging holes and I've never seen one Plenty of sapphires, zircons, garnets, topaz etc - but never a pink sapph or a ruby. The volcanoes up here obviously spewed up magma without enough chromium in the mix. A mate who had a machinery lease on the field here found a few small pink ones and I was shown a stone that had an area of definate reddish-pink in it but I've never found one myself.

But they're hiding out there somewhere.....

 

[Heatho]

I've seen enough Aussie rubies and pink sapphs to know what they look like under UV light. :Y:

All the years I've spent digging holes and I've never seen one Plenty of sapphires, zircons, garnets, topaz etc - but never a pink sapph or a ruby. The volcanoes up here obviously spewed up magma without enough chromium in the mix. A mate who had a machinery lease on the field here found a few small pink ones and I was shown a stone that had an area of definate reddish-pink in it but I've never found one myself.

But they're hiding out there somewhere.....

NSW has some quite rich ruby areas, Cudgegong River has a lot but mostly very small fragments, there was a commercial lease in Barrington Tops, Kerry Packer had a lease on his proprty at Ellerston which turned up quite a lot of very high quality stones. Glen Innes area has pink sapphs too, they are quite common in NSW, though I've never found one either.

 

[Pat Hogen]

What I had seen of the Barrington Tops purple sapphires and the Ellerston sapphires they were mostly very small stones of up to 1/2 ct. Some perfect greens as well but very small.

 

[Heatho]

In my opinion all pink, red, purple sapphires should either be called rubies or pink sapphire, the only thing that really separates them is the hue and colour saturation... Anyway they are what they are and it is a bit subjective.

Interesting article this one.

http://www.minersoc.org/pages/Archive-MM/Volume_60/60-401-623.pdf

 

[PeZ0]

Hi Guys, my first post in this section so bear with me if I am out of format. And thanks for the forum.

So I came across a patch of potch? , At a known opal area. Colours of potch are typically brown and grey.

Theres a lot of transparent lines throughout the rock and am going through a lot of it just trying to find colour to warrant getting serious about looking for more and how.

In this particular area the potch is pretty much under the top layer of grass. Water is flowing beneath this layer which is about 1mtr thick.

But from the rock I am allowed to freely look through I have found the following.

So my question more so relates to what would one do if this is the situation and you would say Yes thats Opal? Would you start digging/drilling/exploring more?

Thanks very much for the opportunity to post and receive some info.

 

[Lefty]

I'm not an expert on opal but some of that certainly looks like some kind of opal or opalite to me.

 

[Schultzy33]

Hi everyone Im new to the forum and need help identifying a couple of minerals. The first mineral is highly magnetic and thought it may be some sort of hematite or pyrite but not real sure and the second mineral is metallic in appearance and glows ruby red under light and has no magnetic properties as I thought it may be garnet. Any help would be appreciated. Thanks all

 

[Phil_In_Boots]

Hi Schultzy33

Welcome to the forum!

Not sure about the first pic but the second one looks like a crystalline form of tin dioxide called Cassiterite. Being tin, it should feel quite heavy when one of them is dropped into your hand. When you look at it some of them can show a red colour. It's really quite nice stuff and you look like you have a couple of nice pieces there.

Philip

 

[deadpan]

I found this stone swirling in my pan after a cleanup a couple of days ago.
Im pretty sure its not just a glass fragment so any help identifying it would be very much appreciated.
I panned it in Broadford,Vic.
Mick

I know black spinel is abundant in Australia but do you get much coloured spinel around the ruby/sapphire areas ?

 

[Mick Cov]

Im a novice when its comes to gemstones but hopefully someone here will be able to answer that.

 

[Lefty]

I found this stone swirling in my pan after a cleanup a couple of days ago.
Im pretty sure its not just a glass fragment so any help identifying it would be very much appreciated.
I panned it in Broadford,Vic.
Mick

I know black spinel is abundant in Australia but do you get much coloured spinel around the ruby/sapphire areas ?

Hi deadpan.

In all the years I've dug on the Anakie field, I've never seen it or heard of it. Plenty of black spinel but never the coloured stuff. I haven't heard of it coming from other sapphire producing areas such as New England or Lava Plains either. It's possible that it exists in Autralia but I'm yet to see any.

Cheers

 

[deadpan]

I found this stone swirling in my pan after a cleanup a couple of days ago.
Im pretty sure its not just a glass fragment so any help identifying it would be very much appreciated.
I panned it in Broadford,Vic.
Mick

I know black spinel is abundant in Australia but do you get much coloured spinel around the ruby/sapphire areas ?

Hi deadpan.

In all the years I've dug on the Anakie field, I've never seen it or heard of it. Plenty of black spinel but never the coloured stuff. I haven't heard of it coming from other sapphire producing areas such as New England or Lava Plains either. It's possible that it exists in Autralia but I'm yet to see any.

Cheers

Thanks for replies gents.
I'm amazed by that Lefty as coloured corundum and spinel are normally found together in other gem producing regions of the world.

 

[Lefty]

I found this stone swirling in my pan after a cleanup a couple of days ago.
Im pretty sure its not just a glass fragment so any help identifying it would be very much appreciated.
I panned it in Broadford,Vic.
Mick

I know black spinel is abundant in Australia but do you get much coloured spinel around the ruby/sapphire areas ?

Hi deadpan.

In all the years I've dug on the Anakie field, I've never seen it or heard of it. Plenty of black spinel but never the coloured stuff. I haven't heard of it coming from other sapphire producing areas such as New England or Lava Plains either. It's possible that it exists in Autralia but I'm yet to see any.

Cheers

Thanks for replies gents.
I'm amazed by that Lefty as coloured corundum and spinel are normally found together in other gem producing regions of the world.

Yeah, I'm not sure how to explain it either. Perhaps someone else here might have an idea. One thing I've noticed is that sapphires from other pars of the world often (though not always) seem more of a pastel shade than ours. I don't think there's any chemical difference between black spinel and coloured spinel, I think they are both magnesium aluminum oxide - maybe there's a relationship between our more deeply coloured sapphires and our spinel that accompanies them usually being black?

 

[user 4386]

Hi every body can anyone identify this for me I have people saying slag but it's weird for slags specially those lines inside of it an it's magnetic as well

An it weighs dry 725.0
An 380.5 wet
Ahah
https://www.prospectingaustralia.com/forum/img/member-images/11799/1516434456_img_0664.jpg
https://www.prospectingaustralia.com/forum/img/member-images/11799/1516434457_img_0665.jpg

An there's this one as well they saying black obsidian I did a gravity test it's 3.106382978723404 after it's been divided for the site but it won't work for me sorry guys an girls

https://www.prospectingaustralia.com/forum/img/member-images/11799/1516434902_img_0669.jpg
https://www.prospectingaustralia.com/forum/img/member-images/11799/1516434902_img_0671.jpg

I don't know if you got an answer, but the texture inside it is very much like what one gets in slags and natural glasses, when instead of staying amorphous glass they start to crystallize over time.

 

[user 4386]

I'm not an expert on opal but some of that certainly looks like some kind of opal or opalite to me.

It is definitely opaline silica and probable chalcedony (microquartz). If from, say, the ridge north through Coober Pedy, or Stuart Creek etc be wary. Many of the opalfields in that area are overlain by a silica rock called silcrete, which is much more continuous over wide areas. The silica in it looks a lot like this - in fact one is a dead ringer. I am not sure that silcrete is a direct indicator of underlying opal though, In a similar setting at White Cliffs I have seen opal broken up into old gravels and only then covered with silcrete, suggesting that they did not form at the same time. Silcret often forms right at surface and often has silica fragments cemented by silica (a silica breccia).

 

[user 4386]

Hi everyone Im new to the forum and need help identifying a couple of minerals. The first mineral is highly magnetic and thought it may be some sort of hematite or pyrite but not real sure and the second mineral is metallic in appearance and glows ruby red under light and has no magnetic properties as I thought it may be garnet. Any help would be appreciated. Thanks all https://www.prospectingaustralia.co...5276_7f6e8676-184d-46fb-bcdc-4b4945db2af8.jpg
https://www.prospectingaustralia.co...5277_50cec2e3-c787-491b-986b-e7d47885a3b6.jpg

Hematite and pyrite are not magnetic - maghemite, magnetite and pyrrhotite are. Magnetite is very strongly magnetic and would be my guess. I agree with Phil re the second one - probably cassiterite, some showing classic twins. Very nice!

 

[user 4386]

Spinels are really a huge group and some are iron aluminium oxide, others zinc aluminium oxide etc (green gahnite that you see around Broken Hill) - it is those with aluminium in their formula that form gems (those without aluminium include the common iron mineral magnetite and the main ore of chromium, chromite). The colour differences in the magnesium aluminium oxide spinel that is most common as a gem (and referred to just as spinel) is just minor chromium and iron to give violet to purple, cobalt and iron to give blue, iron to give bluish green, chromium can give pink and dark green, iron bluish-green, chromium pink to red. It is not only the element that determines the colour but where the element occurs in the crystal structure and what other elements occur with it and where they occur in the structure.

Black spinel is cut in Australia (eg Rubyvale, Weld River): https://www.bespoke-gems.com/SacredGeometrics_Gemstones_BlackSpinel.php - it may be the iron aluminium spinel hercynite (less likely the manganese aluminium spinel galaxite). There is a continuous range between the magnesium aluminium and iron aluminium spinels, commonly referred to as pleonaste or ceylonite and like black spinel not particularly attractive (in my opinion).

I suspect (speculate) that the reason for us having black spinels with sapphires is that most of our sapphires probably come out of basalts in which iron is abundant (and in which the iron-rich spinels hercynite and magnetite occur). Coloured spinel appears almost absent from Victoria and Tasmania (with which I am familiar) just the wrong geology (the same problem with rubies). Coloured spinels from places like Burma and Sri Lanka occur with rubies and are often in limestones a different geology.

 

[deadpan]

Well above my levels of understanding Goldierocks, but thanks indeed.