When the mica is used to "enhance friction", what else can it be but a form of particle.
Normally mica is added to help REDUCE friction, along with the polish. When mica is used to pearlize the coverstock, it makes it less elastic so less of the cover is in contact with the lane surface while it is rolling down the lane, compared to a non-mica solid. If less surface is in contact with the lane, there is less friction.
I'm not saying this makes the 2nd Dim a particle pearl, because Storm does not call it that. I am saying this "enhanced friction" mica is used to add friction to the pearlized coverstock, restoring some of the friction lost during making the DImension into a pearlized ball.
--------------------
"None are so blind as those who will not see."