gneiss
foliated, banding
macroscopic mineral grains arranged in altering light and dark bands.
schist
foliated, mineral alignment
mostly visible flakes of mica oriented nearly parallel, creating a "schistose" texture. Sparkly appearance.
phyllite
foliated, mineral alignment
microscopic flakes of mica oriented parallel create a sheen (slight reflective surface).
slate
foliated, mineral alignment
microscopic flakes of mostly mica (smaller than those in phyllite). Parallel orientation creates "slatey cleavage" planes of weakness.
metaconglomerate
nonfoliated
visible pebbles (conglomerate texture) and Pebbles often deformed (squashed).
quartzite
nonfoliated
very hard (scratches glass)
Commonly white, pink, buff, brown
marble
nonfoliated
composed dominantly of calcite or dolomite which has been recrystallized.
Reaction with HCl
anthracite coal
nonfoliated
black and shiny
irregular "conchoidal" fracture
glassy appearance