Furnace, iron bars, stone grinder, (Cauldron?) generating underground

I was flying and teleporting around in my newly created world with the seed -9102780797200372730, with ESP on that allowed me to see storage blocks. I saw a storage block underground, so I started digging down and found a furnace. After entering spectator mode, I saw other unusual blocks underground such as a stone grinder, what looked like a cauldron, and iron bars. At the coords -17763, 90, 10133, by digging down for around 10~20 blocks, you should eventually see a furnace. I created another world to make sure it wasn't a one time glitch, and the things were still there.