Well, specific gravity performed

SG = 6.22
As I said, it is not exact due to the impurities and bubbles that the material could have, besides that my measurement system is not exact. But the actual value I think should be between 6.2 and 6.8. Discarded Mica for being less dense (2.7) and discarded Silver and Lead for being denser (10.5 and 11.35 respectively).
The most common elements, close to the 6.2-6.8 range according to a table I found are:
Antimony (6.7)
Cerium (6.77)
Tin ore, cassiterite (6.4 - 7.0)
Zinc (6.9 min)
I was thinking that maybe it is not a rock but that it could be the result of a fire that melted some metal and this took the form of some crack in the ground where it remained for decades or even a century. What do you think?
I do not know what metal it is but if it is Antimony it is toxic!... so I have to wash my hands right now.
