Please help Identify Glass like Rock

[Giangiul]

I havent been on treasurenet in far too long but unfortunately I haven't found anything interesting.
My daughter was walking in the field behind our home and it is near an old pond. She found this rock. It looks like a chunk of dirty ice. It was shiny just like it was wet. It looks like it is glass mixed with brown rock. The brown rock on the surface is relatively soft and crumbly but the underneath is pretty hard. The rock is about 8"x 6"x 3". It was sitting on top of the soft ground there, not into it and not in the water.
It's pretty crumbly so I stopped washing it. I thought it looked like quartz but I know very little about rocks/crystals.
My daughter is very excited to see what it might be.

Thank you

 

Amazon Forum Fav 👍

Upgraded Night Vision Monocular Digital Infrared Monocular Telescope for 100% Darkness with 8X Zoom - Grab it through Amazon!

[BurntBear]

The small sections in photo number 3 appear transparent. So much so that I would eliminate Chalcedony altogether. It appears to be slag which can be interesting material. It is the leftover byproduct of smelting ore and is generally a mixture of silica and metal oxides.

 

[Giangiul]

So after it dried there was a white residue. I think it is rock salt!

 

[hvacker]

I know your not supposed to lick rocks but a guys gotta do what a guys gotta do.

 

[huntsman53]

It appears somewhat similar to Stalactites and Stalagmites and I wonder if it could have been coated from a Calcium-Carbonate runoff.


Frank

 

[Las Vegas Bob]

First picture reminds me of dried alkali or even gypsum which we see out here when a water source high in mineral content dries up.

 

[DDancer]

I'll second that it may be a gypsum mineral. The residual coating after drying indicates to me that it may be morphing as water content drops. I thought also that it may be a really large piece of salt peter as well if there is a lot of farm activity around the pond.... but its pretty large and the crystal like bottom does not fit.