I need information on LEGO part #3001 in Milky White with Sparkles
According to a comment from Jan.k 1974 on the source you mentioned (in your comment to 62Bricks answer):


  The milky white brick dates to 2005 and has been been made exclusively for the Allianz Arena (Munich soccer stadium) model in Legoland Günzburg. I remember they sold spares of these in packs of 5 for 1.99 after the grand opening


This is confirmed by Maxx3001 in reply (emphasis added):


  [&hellip;] that's the left brick with slight sparkle in it.


At the time of posting, ND Toys was listing these at $2.39 on BrickLink under "Milky White" with the description:


  MILKY WHITE 2X4 BRICK WITH SPARKLES (from LL park spare parts)


The arena, and the milky white bricks can be seen in this shot on the LEGOLAND website: