Unrealed Default Texture
Have you ever wondered what that greenish bubbly texture in unrealed (Render.utx) is? It turns out to be a real life thing: Cave Pearls. As the name suggests, it's found in caves and it's made of calcite.
I have no idea how that texture ended up as being the default texture in unrealed prior do UE3, but it's nice know what that strange texture is.