Hence, foliation of phyllites differs from the foliation in slates that stems from clay mineral alignment, and unique from foliation in schists because schists often comprise obvious mica grains. Like slates, phyllites show fissility. being an impurity. Pleasing samples of fluorescence may also be noticed in agate and chalcedony geodes. https://top10bookmark.com/story13227788/the-greatest-guide-to-rock-cycle-video-for-kids