❓Your Mineral Identification Questions answered here

Found these near Beaconsfield tas last week. Looks like galena and very heavy but doesn't seem to have a crystalline structure like most of the galena I've seen. Interestingly I threw a couple of bits in the tumbler with some quartz and jasper and the barrel blew up like a balloon overnight. Any ideas on what reaction would cause that?

What is its SG and hardness and streak? Does not look like galena (or gold)

Never mind, found out it's silico manganese smelter slag from the temco refinery across the river. Probably carted there as road base. Another great geological discovery... not!

Curious, something I picked up from the bingara region?

Tin ore? Is it heavy?

LW....

LoneWolf said:

Tin ore? Is it heavy?

LW....

Click to expand...

Yeah pretty heavy, probably twice the weight of a bit of quartz the same size?

Hardness, streak, SG?

Thought so, it looks heavy......Tin Ore as a mixture of 'other' Minerals as well as Tin... Could also contain 'Ruby' Tin, hence the reddish tinge in areas... Then again I may be way off the mark..... Found on the Gem side or Gold side of Bingara?

LW....

Wasn't Ruby Hill area was it? I always thought Bingara was a goldfield (and diamond field) not a tinfield - do both gold and tin occur in the area (they would not occur in the same deposits)?

Possibly this might interest you:

http://brovey.yolasite.com/resources/Bingara-Barraba_Geo_tour.pdf

LoneWolf said:

Thought so, it looks heavy......Tin Ore as a mixture of 'other' Minerals as well as Tin... Could also contain 'Ruby' Tin, hence the reddish tinge in areas... Then again I may be way off the mark..... Found on the Gem side or Gold side of Bingara?

LW....

Click to expand...

Gold side, surrounded by extensive aluvial workings and close to 3 copper mine shafts..
What about chromite?

goldierocks said:

Wasn't Ruby Hill area was it? I always thought Bingara was a goldfield (and diamond field) not a tinfield - do both gold and tin occur in the area (they would not occur in the same deposits)?

Possibly this might interest you:

http://brovey.yolasite.com/resources/Bingara-Barraba_Geo_tour.pdf

Click to expand...

Not ruby hill...it fractured pretty easy with a small pick..

goldierocks said:

Wasn't Ruby Hill area was it? I always thought Bingara was a goldfield (and diamond field) not a tinfield - do both gold and tin occur in the area (they would not occur in the same deposits)?

Possibly this might interest you:

http://brovey.yolasite.com/resources/Bingara-Barraba_Geo_tour.pdf

Click to expand...

I had a rough idea on that info but I didn't know the serpentine carried gold solutions. This makes sense to a particular shaft that was dug into an area of black serpentine. The old guy that dug it was really short and named stumpy. Apparently was getting good gold and only stopped digging because of to much water.
30 years later and the springs have dried up...I wonder lol

If it in the serpentinite, chromite is probable.

Hi all. Wondering if anyone would like to have a crack at identifying this stone. 5mm diameter. Almost jet black but may have a blue hue when backlit with led torch. Hard & heavy. Scratches glass. Thanks in advance. Found panning gully in Chichester SF NSW. Thanks in advance.

I am thinking it is spinel?

Im thinking Spinel too...
Try it under a different light source, as LED is usually in the Cool White spectrum and may throw off a Blue tinge on the edges...

Spinel is a good indicator to Sapphires....

LW....

Thanks LW! I will try under different light as suggested. Would be great to find a sapphire or zircon in this spot. I think I will persevere. Thanks :Y:

Im with Lone Wolf, it looks like Spinel

Looks a bit like spinel - SG would help determine, also it will scratch quartz (almost as hard as topaz).

Can occur with ruby in some areas but not others - if derived from igneous rocks they often occur together (if the magmas are relatively deficient in sodium and potassium relative to aluminium, aluminium oxide may form as the mineral corundum = ruby and sapphire, or may combine with magnesium to form spinel). However often they are simply brought from depth in the magma. However these things are more true of sapphire, as in eastern Australia, where rubies are very sparse - many important ruby fields of the world instead occur in limestone.

If you have a read through goldierocks excellent thread titled ' Series on identifying Minerals' it may be of some help.... An SG test will be one of the best tests you can do besides a 'scratch' test which you have already done (scratches Glass) .... Both of these methods will determine in most cases what it is...

LW....