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Does it feel relatively heavy, average or light?

Do you know the hardness range?  Can you scratch it with a fingernail, a copper penny (1981 or older), a modern nail, a pocket-knife blade or a piece of glass?

What is the size of the specimen?

If you scrape it on an unglazed piece of porcelain, does it leave a color?

Do you know the general area where this was found?

There are a lot of silvery grey minerals, metals, and metalloids.   The above information will help narrow down the options.

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OK, so the hardness is 5.5 or less. Can you scratch it with a copper penny or your fingernail?

if it leaves a color other than steel gray on an unglazed porcelain tile, that would be very diagnostic.

I assume that weight is avoirdupois and not Troy?

If you can immerse it in a calibrated tube and get the volume and then re-weigh it in grams or grains, that would allow a calculation of density or specific gravity.  At a guess, about 3” x 0.5” x 0.25” x 2.54 cubed cm3/in3 equals about 6.15 cm³. 1.8 ounces times 28.3495 g/ ounce equals about 51 g which then works out too about 8.3 g/cm³.  

Silver would be about 10.5, galena (lead ore) is about 7.5.  My density estimation could be way off. But if you can scratch it with your fingernail, then it has a hardness of 2.5 or less.  Silver and lead both fit this hardness. Silver will be a more silver white streak whereas lead will be a lead gray streak on a porcelain tile (unglazed).  Depending on the actual density or specific gravity and hardness, there are a couple other options.

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1 minute ago, snakejim said:

Maybe platinum or aluminum? If it was lead or silver and in the ocean it would be coated black due to oxidation.

I am thinking it’s a little too heavy for aluminum.  Aluminum would have a specific gravity around 2.7.  A chunk of aluminum that size shouldn’t even weigh an ounce.  The black oxidation on silver crossed my mind.  However, Lake Constance (Bodensee) is one of the larger freshwater lakes in Europe. So without the salt, silver shouldn’t oxidize as rapidly.  Platinum is harder and would not be scratched by a knife blade.  However, platinum ore would be about the same density as silver.  But, platinum nuggets that size are as rare as hens teeth.

I am thinking the streak color looks a little on the darkish grey side.  That could just be the photograph and lighting.  But, I am leaning towards galena right now.  However, I would like to have a better idea of hardness and density before deciding.

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