Platinum or silver.

[Diggertom]

Went out with my 705 today around Adelaide, in a park and around some old gravel, got this rock.

Almost chucked it away thinking hot rock, and I decided to brake open.

It's pretty heavy for its size, no scales though.

Any clue? Sorry bout photo quality.

 

[Reeks]

Tarnished like alluminium. Almost 0% chance its platinum.
Spec grav test will give you your answer

 

[Goldpick]

Almost looks like Galena, bit hard to tell without a clearer shot. Is it rather heavy?

 

[Diggertom]

Yea it is pretty heavy.

Reckon I'm gonna need to do specific grav test

Tom

 

[Jon]

Looks like really old lead. Some real old lead can go a bit weird at times. Might be but who knows!?

 

[Diggertom]

I chucked a flame on it to see if it would melt like led, didn't melt though lol

Tom

 

[Diggertom]

Also it chucked a reading of 30-32 on my 705.

18c goes at 22-24 and 22c goes at around 28-30.

I tested some led and that went at 28 with no movement.

 

[Heatho]

Mate if it were Platinum it would be very heavy like Gold, actually Platinum is heavier. You could try a specific gravity test, if it is a Platinum Group Metal or an alloy of PGM's it will still be very heavy and very hard. PGM's take a high temperature to melt.

Simple SG test. http://johnbetts-fineminerals.com/jhbnyc/articles/specific_gravity.htm

Platinum is found in Australia and so are a few other PGM's, it is quite rare though. There is an alluvial Platinum mine in NSW near Condobolin, also a few other deposits of PGM's in beach sand and with some Gold deposits. An example is Osmiridium in Tasmania in alluvial deposits.

 

[XIV]

Looks very much like Galena to me too,
if it is, it is lead ore, + silver
silver is slightly more heave than lead, hints why you may get a slightly higher gravity test.

 

[dazza513]

Don't laugh but could it be some old tungsten slag?

 

[Goldtarget]

I'm going to throw in my two specks worth and call it a zinc or zinc bronze alloy perhaps. It would explain the shine, the grain, the shape, the shine and higher reading. What sort of flame did you use? Chuck a grinder on it and tell me how or if it sparks and I'll put you in the ball park. These pesky non discript metals usually don't need too much to decipher. Spark test is the quick way home. The fact it was so close to civilisation I'm guessing it's not too exotic.

 

[gcause]

Natural lead.

 

[ferrousfinder]

Antimony or Galena. Hard to tell from the photos. Streak tests from all the above guesses should help narrow it down.
Good luck.

http://www.minerals.net/MineralMain.aspx

 

[axtyr]

If you remove that crap off the top I think you'll find it's a one dollar coin. Definitely aluminium bronze.

 

[SnJ]

If you remove that crap off the top I think you'll find it's a one dollar coin. Definitely aluminium bronze.

Ha! You made me LOL mate! People around me wondering about my sanity.