When I was little, my father had built a fish pond in our yard, which he decorated with various rocks and such. One stood out in particular. It was not like anything I had ever seen. It was very dull on the outside but if you looked up close, you could see the various tunnels and pockets with bits of areas that sparkled.
I never found out where it came from. I'm in Chicago and I highly doubt it was found here. All I know is that I'm now in my 40's and I have brought this piece (which weighs 50-75 pounds) with every time I have moved. It still continues to fascinate me to this day.
I've always had a love for rocks and minerals but sadly I'm just getting started on the hobby. Better late than never! Could someone tell me what this is called? Where it might have come from? I'd love to know something about this. Thank you so much in advance