❓Your Mineral Identification Questions answered here

[Pete's Pick]

Interesting suggestion.
Possibly.

It is heavier than quartz but not tin like heavy and it shows no magnetic susceptibility to a rare earth magnet.

 

[Dave79]

Looks like tourmaline in structure

 

[RockRat]

Looks like tourmaline in structure

correct Dave, Schorl is black tourmaline :Y:

 

[Salinger]

Could I please have some opinions on this?

Picked up by my late father around the Granite Belt, QLD.

Maybe glass?
We have a couple of other larger pieces with a more brown than yellow tint.

*** Apologies for the huge photos.

 

[MegsyB007]

Topaz? Cassiterite? They're both found around that area, as well as smoky quartz around Swipers Gully.

Goldierocks made this post earlier - try some tests and post the results - it will help him to identify them when he visits this thread.

"Rocks are not minerals - to identify a rock, we first have to identify the minerals it is made of. To identify minerals we use things like hardness, streak (its powdered colour), colour, lustre, is it magnetic and whether it fizzes with acid to do this. If a rock is made of more than one mineral, we need a hand lens to be able to see the properties of each mineral separately. I have described how we do this in detail in about eight detailed accounts, each numbered. Do a search on this site of "Series on identifying minerals" under my name.

Tests like hardness and streak require nothing specialised to determine them, so if you could at least have a go at these before posting."

Best of luck.

Cheers,
Megsy

 

[Pat Hogen]

I would facet that; thinking it is obsidian but it could turn out to be topaz.

 

[Salinger]

Thanks Megsy and Pat!

As for hardness, I can't put a mark in it with a coin so I broke out a pocket knife and managed to put a nice blunt spot on the knife but no mark left on the surface of the rock. I tried to scratch it with the tip of the blade, but it didn't leave a mark at all.

I could try a streak test, but the hardness of the rock leads me to believe that it wouldn't leave anything behind.

Dad reckoned it's topaz, but he was also prone to telling a whale of a tale, so it was always best to remain skeptical when he'd start up.

He left behind some interesting bits and pieces. Lots of small sapphires and garnets (I think), a few chunks of the stone I posted above all of a similar size.
And quite a few points of black quartz (I think), one of which I have with me:

 

[MegsyB007]

Topaz has a MOHS of 8 and Quartz is a 7.

Try scratching the topaz with quartz - one will be scratched and the other (topaz) won't scratch.

I think you may have both there - possibly topaz (first pic) and smoky quartz. Maybe even Cassiterite... That's 6-7 on the MOHS scale.
Hard to tell from just pics, and they're similar colours.

Topaz is also cold when touched to the lips, and has a waxy kind of feel to it.

Keep testing to eliminate or ID them.

Regards,
Megsy

 

[Salinger]

Great info, thanks. The clear one scratched the black one, but not the other way around.

If this turns out to be topaz, I'd love to find someone local to facet it.

 

[MegsyB007]

Could be topaz then... That's assuming the black one is quartz! lol

Not sure where you are. You could try Wally69 on this forum - he's in NSW or Lefty is in WA.

When you have 10 posts you can PM them to ask.

Cheers,
Megsy

 

[grumpygold]

some look a yellow/ orange colour maybe citrine does any one know if thats found in the said area, imo

 

[Pat Hogen]

What is Lefty doing in WA? Looking more than likely to be Topaz. A specific gravity test will help, if you have a set of scales that measure in grams/carats. Where did you not say that you are living, which state, where?

 

[Dihusky]

They look to be some very interesting pieces of rough, the Granite belt is known for its Topaz which tends to be light brown, clear of blue, we were there over Christmas and it's getting harder to find now, but still there. The first test to confirm is Specific Gravity, Topaz is 3.49-3.57 whereas Quartz is around 2.65, if it turns out to be quartz then you'll likely have Citrine.

Topaz is an orthorhombic crystal so it can present striations running parallel the long axis, it also has low 'tenacity' meaning it can easily fracture/cleave meaning it breaks easily at right angles to the long axis. Looking as the erratic fractures in these crystals would indicate that quartz might be more likely, but an SG will be the quickest confirmation.

If you're in SE Qld, more than happy to help identify them.

 

[LONEWOLF]

Lefty in WA maybe for a holiday...

LW.....

 

[Lukefly]

Hi Everyone,

I very new to rock hunting. It is a hobby I am starting was my young son. We are looking to collect rocks and them tumble them. It was suggested that I look at Scarborough beach QLD for chalcendony. Can a few of the more knowledgeable people let me know are these rocks chalcendony, or am I just picking up normal quartz. Please forgive my lack of appropriate geological terms.

Cheers
Luke

 

[Smoky bandit]

From the pics it looks like Quartz.The upper and lower on the bottom right of the pic may be?And possibly the bluish one in the middle.But I'm only an amateur.
The stuff from scarbrough is ....if you look hard enough... a translucent orange /red.. erfect:

 

[user 4386]

Hi Everyone,

I very new to rock hunting. It is a hobby I am starting was my young son. We are looking to collect rocks and them tumble them. It was suggested that I look at Scarborough beach QLD for chalcendony. Can a few of the more knowledgeable people let me know are these rocks chalcendony, or am I just picking up normal quartz. Please forgive my lack of appropriate geological terms.

Cheers
Luke

https://www.prospectingaustralia.com/forum/img/member-images/14274/1546810916_img_5323.jpg

Some may be chalcedony not quartz (strictly chalcedony is quartz, just a very fine-grained variety). But the real question is - what do you think they would look like if you tumble them?

 

[user 4386]

My dad gave me a bucket of interesting rocks on Christmas day, that he said were some his dad had found years ago (he died in 1991, so he wasn't kidding!).
Unfortunately dad didn't know from where he got them, but I'm pretty sure it's not pyrite on it, that he said someone had suggested.
It's not brassy enough for pyrite, or the right shape, in my opinion.
I think perhaps it's tin. Which I thought was strange when it peeled away into clear layers. Can someone please confirm this a characteristic of tin? (See pic in hand).
And is it likely to have gold mixed with a tin deposit like this one, to crush and pan it?

https://www.prospectingaustralia.com/forum/img/member-images/13534/1545922566_rocks.jpg
https://www.prospectingaustralia.com/forum/img/member-images/13534/1545922592_rocks2.jpg

Thank you.
Cheers,
Megsy

It is clearly a mica of some type. Definitely not pyrite, or tin. Tin does not occur naturally as tin metal, and the oxides and sulphides it occurs in do not look like tin metal.

 

[user 4386]

Hi XIV,
I'm no expert, but I'll have a go at some of these for you to look them up.
The first one looks like malachite (or an unusual black opal with only a green flash), the second one looks like opal potch, don't know the third one (opalised wood maybe?), and the fourth one looks like Amazonite.

Perhaps the experts can confirm or give alternatives?

Cheers,
Megsy

 

[user 4386]

Hi XIV,
I'm no expert, but I'll have a go at some of these for you to look them up.
The first one looks like malachite (or an unusual black opal with only a green flash), the second one looks like opal potch, don't know the third one (opalised wood maybe?), and the fourth one looks like Amazonite.

Perhaps the experts can confirm or give alternatives?

Cheers,
Megsy

Doubt those IDs but it is impossible to give useful answers to people unless they do some of the hard work first (photos are always inadequate, you also need streak, hardness, SG etc). Do a search on "Series on identifying minerals" under my name.