Hubby found this at Nelscott Beach around 35th street SW at low tide in February, 2010.
It appears to be a nail, set in concrete of some type, encased in a tube of sorts. The tube feels like stone, the concrete is getting softer the dryer it becomes. The nail does not have tarnish, does not smell of brass and does not conduct taste or acid to the tongue.
Is this from a survey post? For now we will go with it was a Nail that King David gave to his son to build the temple, since that sounds alot more fun. It seems to be antique and fossilized.
What do you think?
+Angie Wright
Pebblekeeper 
The copper in the brass would react with nitric acid if you could get some. Just do a small fleck off the nail. Gold has a higher density, but that would be hard to test since it's encased in stone. Also, hard to tell from pics but it looks tarnished to me which would indicate NOT gold since gold never tarnishes. I'm curious to see what stories the boys can come up with to explain it and where it came from. They will certainly be more interesting than whatever the truth may be no matter how interesting the truth is!