I found a rock with a density of 16 g/cm3. It's non-magnetic and conducts heat well. What metal could it be?

Question

The ore is dark gray, almost black with obvious flecks in it. The flecks appear more silver colored than yellow/gold colored and are crystalline in structure. I found the rock in a parking lot in Texas a few years ago and kept it because it weighed so much, about 80 g in a small rock. I initially thought it might be a meteorite. Specific gravity of pure gold is about 19 while pure platinum is 21. Density of rock is valid though maybe not precise; I used displacement d=m/v, to arrive at density using a graduated cylinder, accurate to 1 ml. I put a small propane torch to the rock; it got very hot and held the temperature well but didn't melt. I wasn't measuring temperature and can't tell you how hot the torch got the rock. (There was no plum bob with the initials A.S. carved in it either.)

Answer 1

If that density is accurate, there are not many things that dense. Here is a list:

Tantalum 16.65

Uranium 18.95

Gold 19.32

Tungsten 19.35

Plutonium 19.

Neptunium 20.2

Rhenium 21.04

Platinum 21.45

Iridium 22.4

Osmium 22.6

I think the most likely is tungsten in some form.

Answer 2

Whatever the rock is i'm certain it will contain lead ora galena. This is a very dense mineral and would explain the dark grey colouring in the rock

Answer 3

I suspect it's slag from a smelting plant. No natural ore is that dense (Galena ... Lead Ore is 7.5g/cm^3). It seems that your measurements may not be reliable.

The density of iron is 7.87 g/cm^3 and the density of lead is 11.35 g/cm^3

Slag is often used to surface roads and parking lots.

This site might help http://www.mininglife.com/Miner/general/...