Subject: What metal solute turns water a tea like color?

For a deveice that I am working on, we had to build a battery.  We used a 
250 mL beaker of 1M solution of Cu(NO3)2, a U-tube filled with 1M NaNO3 
with a semi-permeable membrane on both sides, and a 250 mL beaker of    1M 
Al(NO3)3.  We placed a copper pipe in the Cupric Nitrate solution and what 
I thought was an Aluminium rod in the Aluminium Nitrate solution.  This 
cell evolved a steady 0.994 Volts.  However, I accidentally set a magnet 
down near my supposed Al rod and much to my surprise they attracted each 
other.  I decided to connect the Copper pipe and the other metal together 
and let it run overnight.  12 hours later, I returned and saw that the 
previously clear Aluminium Nitrate solution turned a tea like color with 
tiny bubbles on the surface.  The copper solution was the same blueish 
color.  I disconnected the two metals and found that the cell no longer 
produced a voltage.  I took a piece of steel wool to the end of the 
unknown metal and placed it back into the brown solution.  The cell began 
to evolve a steady 0.554 Volts.  What is this metal?

Re: What metal solute turns water a tea like color?