These vials of sand are among the most odd things in my collection. They come from the filming locations of A New Hope and Return of the Jedi.
Tunisia / Lars Homestead 
Buttercup Valley / Sarlacc Pit
The sand from the first vial comes from Tunisia, at the filming location for the Lars homestead in A New Hope. I got it with a limited edition DVD for a documentary called “The Force Among Us”.
The second vial contains sand from Buttercup Valley in USA, where they filmed the scenes with Jabba’s barge and the Sarlacc pit in Return of the Jedi. I got it from Trooperbay.