Need help identifying this metal please

[Martijn]

Is it just me or does that 'zinc anode' look like a cast bar with a mat and slag layer on it? laying upside down. I can see two lines on the side corresponding to parts that have different color and structure. Is that normal for sacrificial anodes?

 

[Yggdrasil]

Is it just me or does that 'zinc anode' look like a cast bar with a mat and slag layer on it? laying upside down. I can see two lines on the side corresponding to parts that have different color and structure. Is that normal for sacrificial anodes?

To me it just looks old and used.
Like they usually look when or before change.