❓Your Mineral Identification Questions answered here

[user 4386]

There are a number of different causes of colour, incorporation of traces of other elements is only one. In the case you mention:

"some varieties of quartz - like smoky quartz and amethyst - actually derive their beautiful colors from defects in their crystalline structures".

http://www.webexhibits.org/causesofcolor/12.html

 

[Squint]

Posted this photo in my trip thread but thought I might get a better response here. Found these amongst black tourmaline, brilliant sparkle, scratches a beer bottle easily. What the chance they are diamonds?

 

[7.62marksman]

Hope for your sake they are mate fingers crossed

 

[Squint]

Bitter sweet though. The one in the middle included a sieve full of shards. Think I was a little over zealous with the mattock. Just my luck. 8.(

 

[user 4386]

Posted this photo in my trip thread but thought I might get a better response here. Found these amongst black tourmaline, brilliant sparkle, scratches a beer bottle easily. What the chance they are diamonds?https://www.prospectingaustralia.com/forum/img/member-images/10432/1531642876_img_20180714_134826_748.jpg

Sadly unlikely. Quartz will easily scratch glass - try scratching quartz with them (or vice-versa). Although diamonds can fracture and it is conchoidal (so it is like quartz in this respect), alluvial diamonds commonly still show one or more crystal faces (unlike alluvial quartz):
https://c8.alamy.com/comp/DAW00W/rough-alluvial-diamonds-south-africa-DAW00W.jpg
The lustre of diamonds is adamantine, not vitreous (glassy) like quartz, most visible when you have these minerals side by side. Specific gravity of diamond is 3.5 (not 2.9 as with quartz). Diamonds are hydrophobic (water cannot wet their surface) and readily adhere to grease and oil (commonly use in separation) - I know of no other mineral that sticks to grease.

Take the chance and try scratching quartz with one....diamond will easily scratch quartz deeply.

 

[Squint]

Just tried your suggestion. Middle and top left both scratched a quartz crystal. The top left more easily which was a surprise as the middle one seemed to leave a deeper scratch in glass. These just seem different to other things I've found. Maybe I'm just too hopeful. :rainbow:

 

[Feathers12]

Hello everyone .I was panning for gold today and I found this stone.I have no idea what it might be.I was hoping someone in this forum might be able to enlighten me thanks?

 

[user 4386]

Just tried your suggestion. Middle and top left both scratched a quartz crystal. The top left more easily which was a surprise as the middle one seemed to leave a deeper scratch in glass. These just seem different to other things I've found. Maybe I'm just too hopeful. :rainbow:

Interesting - did you try the reverse (to scratch them with quartz)? Still very doubtful about diamond but there are other possibilities (eg topaz). If you had a bit of that or corundum and you scratched them with it, it would also be a good test (it is worth keeping a set of index minerals). Can't do much else at a distance I'm afraid. SG is the only other useful property fairly easily determined that might be diagnostic (3.5 for topaz).

 

[user 4386]

Hello everyone .I was panning for gold today and I found this stone.I have no idea what it might be.I was hoping someone in this forum might be able to enlighten me thanks?https://www.prospectingaustralia.com/forum/img/member-images/12461/1531649685_img_20180715_182738.jpg

It is impossible to identify anything like that based on a photo. Do a search here on "Series on identifying minerals" and give us some properties (particularly hardness - SG if you can).

 

[user 4386]

This is the ultimate answer for a geo, but not cheap!

https://prospectors.com.au/collections/hardness-points/products/moh-scale-hardness-points

Unfortunately for hard, transparent, fairly colourless minerals, this and SG (described in my series on identification and inexpensive) are really the only answer. The cheap way with hardness is to get a fragment of corundum, topaz, quartz and a steel knife blade and use it as a test kit (not as good as this, but fairly diagnostic). It is not a lot of good just sending photos of things meeting this description - no one can identify them at a distance using photos (rarely perhaps, eg if they show crystal faces or cleavage).

An intermediate cost alternative is:

https://www.pilbarageology.com.au/products/Mineral-Hardness-Testing-Kit.html

 

[Heatho]

I'm almost 100% certain they are not diamonds either. You can buy electronic diamond testers on ebay for around $30, I've seen them in action and they do work. I've also seen stones posted on here that looked a lot more like diamonds that proved not to be as well.

 

[Mungoman]

Any idea what this one is? It's in a mineral collection

It has as you can see, four facets and it's largish - that's about all I know.

 

[user 4386]

Any idea what this one is? It's in a mineral collection

It has as you can see, four facets and it's largish - that's about all I know.https://www.prospectingaustralia.com/forum/img/member-images/2730/1531699959_31439024.jpg

It is difficult to identifybased only on a photo. Do a search here on "Series on identifying minerals" and give us some properties (particularly hardness - SG if you can - SG is completely non-destructive). However perhaps you don't have access? Some more photo views in detail might help. Not sure what you mean by facets - they look like cleavage planes and might help identify it with more photos.

One guess:

http://www.healingcrystals.com/images/rhodonite natural4.jpg

And another:

https://upload.wikimedia.org/wikipe...0px-The_Searchlight_Rhodochrosite_Crystal.jpg

Some feldspars can also look a bit like that in coloured varieties. But it is pure guesswork without any other info.....

 

[Mungoman]

Thanks for the quick reply Goldierocks.

As you've guessed, I don't have access to the stone to do a SG test (a marvellous form of ID), but I was hoping that the stone could be ID'd to a certain degree by the crystalline form.

The bulk of it seems to be four sided, and the miniature crystal just above the '7' in the tag resembles a pyramid with 4 sides.

As quartz generally has 6 faces to a gem crystal, I wondered if I could get it narrowed down by it's colour and it's crystalline form.

Thanking you, Jon.

 

[user 4386]

Thanks for the quick reply Goldierocks.

As you've guessed, I don't have access to the stone to do a SG test (a marvellous form of ID), but I was hoping that the stone could be ID'd to a certain degree by the crystalline form.

The bulk of it seems to be four sided, and the miniature crystal just above the '7' in the tag resembles a pyramid with 4 sides.

As quartz generally has 6 faces to a gem crystal, I wondered if I could get it narrowed down by it's colour and it's crystalline form.

Thanking you, Jon.

I did not see that, but it would require a much bigger photo of that area before any further guesses could be made.

 

[Dihusky]

Hello everyone .I was panning for gold today and I found this stone.I have no idea what it might be.I was hoping someone in this forum might be able to enlighten me thanks?https://www.prospectingaustralia.com/forum/img/member-images/12461/1531649685_img_20180715_182738.jpg

I have some similar looking material which is Tourmalited Citrine, do a SG test first then a scratch as detailed in other posts

 

[Lefty]

From where I'm looking, it looks sort of 3 sided, like a tourmaline pencil.

 

[Mr Magoo]

I did not see that, but it would require a much bigger photo of that area before any further guesses could be made.

The image zoom may give more clues :/ . https://www.invaluable.com/auction-lot/large-unidentified-pink-crystal-mounted-867-c-73e4210bb5

 

[user 4386]

Hello everyone .I was panning for gold today and I found this stone.I have no idea what it might be.I was hoping someone in this forum might be able to enlighten me thanks?https://www.prospectingaustralia.com/forum/img/member-images/12461/1531649685_img_20180715_182738.jpg

I have some similar looking material which is Tourmalited Citrine, do a SG test first then a scratch as detailed in other posts

Citrine has no cleavage

 

[user 4386]

I did not see that, but it would require a much bigger photo of that area before any further guesses could be made.

The image zoom may give more clues :/ . https://www.invaluable.com/auction-lot/large-unidentified-pink-crystal-mounted-867-c-73e4210bb5

No, needs far more detail - sorry