How do I remove slate from speciman

[HarryHoudini]

Hi Guys, hoping someone will know the answer.
Today I found a few specimens but surrounded by slate.
Does anyone know a safe way to remove the slate without using hazardous chemicals or crushing?

Cheers

 

[GypsyGoldAu]

Small hammer & chisel?...

 

[XIV]

Hydrochloric acid. When done, tip it into a bucket of water
Then just wash with water.

 

[aussiefarmer]

Hydrochloric acid. When done, tip it into a bucket of water
Then just wash with water.

Does that work for iron stone to ?

 

[HarryHoudini]

And the gold trapped in quartz?

Cheers

 

[Tathradj]

Being careful,
Heat the quartz up until red hot.
drop it in cold water.
Thermal shock will break up the quartz.
Just be careful it does not explode in your face.
The old Timers used to do this.
Also, any rocks that have been in a stream or creek have water
trapped in them. That is why it is not a good idea to use them
around a camp Fire or such.
not good for the Snags I can tell you. They go a bit too crunchy.

 

[HarryHoudini]

Cheers. My job for tomorrow. With full face cover.

 

[GypsyGoldAu]

Sorry HH,...when i read 'specimen', i was thinking of gems, not gold...lol.

Been on too many threads lately i'm losing it ha ha ha.

Hydrochloric works, but a lot slower than say some AliBright aluminium cleaner, and more so on ironstone species. That has Hydrofluoric acid, but this is also more nasty if you don't follow use instructions.

Otherwise, as above re; fire/water.

Gypsy

 

[HarryHoudini]

I think Alibright has been removed from sale.. So I will give fire and water a go.

Cheers

 

[Dignit]

HH
You can still get Alibrite at Supercheap Auto.
Cheers

 

[HarryHoudini]

Cheers.

 

[HarryHoudini]

How long does Alibrite take to dissolve impurities?

 

[Davent]

Hydrochloric seems to work on iron stone here, and quicker than alibrite. Not so good on quartz.

 

[GypsyGoldAu]

Hydrochloric seems to work on iron stone here, and quicker than alibrite. Not so good on quartz.

What i meant Dave, was that hydrofluoric works faster on ironstone than hydrochloric in my experience. I have access to a higher % than alibright though, so that may account for my perception. Agree about the quartz, but i only use it for cleaning the matrix if i'm keeping them, otherwise i free the gold...

 

[HarryHoudini]

Well guys Alibrite from supercheap $20 worked a treat in just two days quartz nearly gone. Leaving the yellow stuff in tact.
Thanks for your help.

Cheers

 

[SWright]

G'Day All

Removing any material from around gold can be problematic. Do you want to extract the gold for processing. If so simple crush the entire rock and pan off. If you want to expose the gold in the specimen remember that all the gold may not be interconnected and even if it is it may end up being very fragile and fall apart anyway. If the gold formed first in the rock and quartz or other material came after then you may have a nice specimen when the gold is exposed but more often than not the gold was deposited in fractures in a vein system and you will end up with potentially an ugly specimen as well as being fragile.

Remember that many specimens of gold in or on matrix are more valuable to specimen collectors than the value of the free gold. You can take a leaf out of the mineral specimen collectors book and carefully remove some of the quartz or slate with a fine grinding tool like a kind of dentist's drill. You will see this technique used on quite a few crystal specimens.

Araluen

(Never underestimate an old person with a geology degree)