Sounds like stone dust (also called decomposed granite)... it's a type
of sand used for underlaying brick sidewalks, patios, and the like.
Were any put in there in recent memory?
When you dump wanter on stone dust, it semi-dissolves, semi-
hardens.....

On May 12, 12:33 pm, "A. Learner" a.learner@earth wrote:
I found a large unlabeled bucket of (leftover?) material in my in-laws'
basement. Nobody seems to remember what it is. It might even be there
when they moved into the place.

The stuff is light grey, granular, gravel-like, with a grain size of
about 0.5 mm to 3 mm. When I soaked a sample in hot water for several
minutes, the grains disintegrated and the sample turned into a dark
grey, muddy mixture.

At first, I thought it was some kind of fine gravel, but gravel doesn't
disintegrate in water. (Does it?)

If we can't figure out what it is, and what it can be reused for, it'll
probably end up in a landfill somewhere. Hate to see that happen.

Does anyone have a guess what the material might be based on the
description?

TIA