Domestically I have sand from FL and HI, and possibly AZ (can't remember)... Haven't tried int'l yet...
Usually no issue if checking the luggage... once when I was much younger... I filled up an empty milk gallon jug full of sand... it put my bags overweight so I put it in my backpack... needless to say, TSA was like what? I wanted to dump it out and send it thru in their trays, but my parents would not let me... so I had to leave it...
[It was too thick for the xray to see thru the sand]