Phyllite
Rock
About it
Between slate and schist: fine-grained but with a silky sheen from tiny mica crystals, and often wavy or crinkled foliation. Common in mountain belts such as the Appalachians.
- Type
- Rock (metamorphic)
- Group
- Metamorphic (foliated)
- Specific gravity
- 2.65–2.8
- Lustre
- silky, pearly
- Colours
- silvery grey, green, greenish grey, black
- Transparency
- opaque
- Cleavage and fracture
- splits along wavy, shiny foliation
Typical values: real specimens vary. For more, see mindat.org.