We retrieved these coral pieces from a lake-salvaged cannon we thought had only been in fresh water, Lake Champlain, in New York. Large pieces together are about 3" x 12", and were toward the rear of the cannon when dislodged. No idea if someone stuck them there or if they grew in place. I suspect due to the cannon-bore shape, it grew in the cannon somehow, but really IHNI. ?? I thought coral only existed in salt water. The white inside part is just like milky Quartz, the mineral, and the weight is about the same.
Yes, the cannon was aboard HMS LYNNET (the one built in 1814) that sank about 1830. The cannon was salvaged in 1949. So was under for about 119 years. Come to think of it, there would have been some water flow through the cannon at least until the vent (small hole near breech) caught enough debris or calcium to stop any flow. The wreck was in very shallow water so breezes would have caused some water flow.
I hope we get a rockhound or geologist to look at this thread. The bland crust around the outside reminds me of geode. I was searching last night and got way off track. I ended up inside a cave in Mexico with quartz crystal the size of telephone poles for about an hour, LOL.
The "crust" looks more like staining from the iron cannon.The photos have too much light to see what the white end looks like.
Reminds me of one of my fave sci-fi movies, Megalith Monsters or something similar. And yes, I'm sure the brown crust is absorbed iron oxide.
The deposits happen through an acid and base reaction. Your metal object in water gives a mild acid, which will react with the dissolved calcium bases to give an insoluble salt. Hang on a bit and I'll work out the formula. Same principle as what happens with water pipes in places like London, which have very hard water. It's why water pressure is kept high.
