Forgotten - but not gone.

The last lot got "recycled" so I thought I'd have another go.  Trouble is - as I admitted recently to A. N. Other; with a combination of "One thing and another"; I let the house get into "a bit of a state" the Other being in XS of 12 months Lockdown.  I kinda forgot this project.
You are viewing the result. 
"Nae Tribble Captain"© - save a few for the next solution.
It occurred to me that I also have two or three other white crystaline solids, I may yet start a Crystal-Farm? 
Unless one of them turns out to be deliquescent?