Is this a Platinum Nugget?

[Dwayne2010]

I was out metal detecting today for gold nuggets on the Fraser River. I cam across this in bedrock. Its very heavy at 9.85 grams. I am having a hard time trying to figure out if its platinum or not. I put it in peroxide and it produces very lazy bubbles. Nothing spectacular, but does bubble. I tried doing the specific gravity thing, but I flunked math. I put it in a vile with 30ml of water and dropped the nugget in which brought it up 1 ml. Not sure what the hell that all means. I tried scraping it with a knife and it damn hard, nothing like lead which is ver soft. So thats where I am at. I stil don't know what it is.

 

[taz42o]

I dont think thats platnium, does a metal detector pick it up? or is a magnet attracted to it?
Here is a link the shows the way to do a specifac gravity test.
The only math is division.

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

Metal Density
Gold 19.3
Silver 10.5
Platinum 21.4
Palladium 12.0
Copper 9.0
9ct 10.9 to 12.7
14ct 12.9 to 14.6
18ct Yellow 15.2 to 15.9
18ct White 14.7 to 16.9
22ct 17.7 to 17.8
Sterling Silver 10.2 to 10.3
950 Platinum 20.1

 

[Dwayne2010]

This was in a deep crack in bedrock. My Garrett AT Gold picked it up at over a foot away with a deep crisp sound. It is non-magnetic.

 

[Dwayne2010]

I did the test. it is 9.85 grams Dry weight and .95 grams wet weight

9.85-.95=10.36 specific gravity

I was able to scratch it on a knife blade, but just barely so its softer then a steel blade and softer then glass when I did the scratch test and a penny does not scratch it. Streak test is grey. Thats where i am at with this. I went to a chart and at the top is Platinum. I guess my next step is to take it to a jeweler and see what they come up with. I should mention that after doing the streak test, the dull coating underneath was shiny. It is heavy like gold.

 

[chuck ky]

i very naive about these things but why would it weigh that much less dry than wet.

 

[Dave~UT]

Could it possibly be a meteorite? I'm not real familiar with all the different classes and varieties. That would be my first guess, though.

 

[Dwayne2010]

Hey Chuck, heck if I know. This is the first time that I have done this. Given the specific gravity of my sample, plus lots of error on my part as I am not math inclined or very bright, I think it is a silver nugget. I am going to try and polish off the tarnish. The more that I consider it being silver, the more sure I am. Silver coins for instance, take on a tarnish like this nugget. hmmm?

 

[ralph]

Go to the prospecting form with this--I've read gold nuggets can become coated with a black coating.

 

[Dwayne2010]

I polished thiss up using baking soda/salt/aluminum foil and boiling in then polishing with tooth paste. This is as good ass I can get it. It sure looks like silver or platinum now.

 

[DiggerODirt]

I am thinking melted aluminum

 

[taz42o]

With the results of your test i would say its silver.
Silver does oxidize black.
They say if you put silver in aluminum foil and spit on it it will produce sulfur dioxide and will smell like sulfur/eggs.
I have not tried it though.

 

[Aarong81]

Silver polishes up extremely bright with a water/baking soda paste. Mix it about the consistancy of tooth paste and rub it in with your fingers and it should shine bright. It would at least support the silver guess short of confirming it.
I just re-read your comments and realized you already did this. Unless it is lower purity, it should've shined easily.