I had one of those last week. Shame of it was that it was someone's first egg. How long does it take an egg to freeze solid anyway? The one I found we originally thought was a sussex egg because we found a second one exactly the same color later that day and I swear there were no eggs in the nest box when I checked that morning. But I've since seen my leghorn lay eggs that size and color and since seen one of the sussex lay a slightly larger, darker brown egg. If I didn't just overlook the egg, it means that it froze solid (and cracked!) in about 4 hours! That seems fast to me.
Tell me about the cold! This morning when I went to let the girls out it was -5 degrees. And that was without the wind chill. They kind of looked at me like I was nuts until I went to go get more straw for the run to keep their little feet somewhat warm. But they were sure happy to get leftover soup for their daily treat this afternoon!