I heard that when you smash the Challenge Rock, once a day it would give you a Star Piece. It will give me Stardust once a day and nothing else. No, I dont cheat, the game was new when I bought it, and it's Black Version 2. Thanks.
Nope. I think Star Piece is incorrect, and was just a typo that's spread to places like Serebii. I get a Star Dust with my Mienshao daily, and my game has not been hacked/ AR'd/ etc.
It's just that it's in BW and not B2W2, you get a Star Piece, and most people just assumed that it was the same in B2W2.
Pinwheel Forest - Bulbapedia - it lists Star Piece for BW and Star Dust for B2W2.
this is not a glitch you always get stardust.
It is the same in all 5th gen games.
star dust is sold for 1,000 while stardust is around 5 times as much monny for selling.