petal dust is very fine in texture, if you are trying to grind your own chalk it is more difficult. Neither one is edilbe, just non toxic, so in that cas it really doesn't matter which one you use. What i do when using chalk, is take a piece of paper (just plain copy paper) and color really thick on it, then take the brush and run through the color to pick up the loose stuff.
Thanks, peg818. I was thinking about ordering the chalk palette from Earlene Moore's website; she has a set that's already powdered. The set doesn't seem to contain a lot of each color, but for $12.00 it seems cheaper than trying to order so many individual containers of petal dust. 
When my MOm uses here chalks from and artists palette she lightly takes a sharp razor knife and gently scrapes the chalk in a downward motion.The powder falls onto a papertowel or paper.
I'm assuming it's in the art section? I was in the cake section and didn't see anything. 
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