What is this picture?

Question

What is shown in this image?

Accepted Answer

corroded copper pipe. # The Green Patina Actually Protects Your Water

That beautiful blue-green coating that forms on old copper pipes—called verdigris—is actually nature's way of sealing the metal and preventing further corrosion, which is why Victorian-era copper pipes can still work perfectly fine after 100+ years. Ironically, this protective layer is so effective that plumbers have to actively remove it if they need to solder pipes back together!

Answer: corroded copper pipe