It's most likely the same chemical formula (so yes, "same stuff"), but phosphors vary quite a bit in their quality based on the synthesis conditions (maybe the "same stuff", or may be better/worse quality than UN's batch).

Thanks, I'll try it!

It "recharges" when exposed to light.

and the "glow time" is only to a value of .32mCd, which is, per their copy, "100x more luminescent than necessary to see with the naked eye"

so more than 30 hours after being charge for 5 minutes in the sun.