text: Cleavage forms parallel to crystallographic planes:
  *Basal, pinacoidal, or planar cleavage occurs when there is only  cleavage plane. Talc has basal cleavage. Mica (like muscovite or biotite) also has basal cleavage; this is why mica can be peeled into thin sheets.
  *Prismatic cleavage occurs when there are  cleavage planes in a crystal that intersect at 90 degrees. Spodumene exhibits prismatic cleavage.
  *Non-Prismatic cleavage occurs when there are  cleavage planes in a crystal that do not intersect at 90 degrees (two non-perpendicular directions of cleavage, e.g 60 & 120 degrees).
  *Cubic cleavage occurs when there are  cleavage planes intersecting at 90 degrees. Halite (or salt) has cubic cleavage, and therefore, when halite crystals are broken, they will form more cubes. 
  *Rhombohedral cleavage occurs when there are  cleavage planes intersecting at angles that are not 90 degrees. Calcite has rhombohedral cleavage. 
  *Octahedral cleavage occurs when there are  cleavage planes in a crystal. Fluorite exhibits perfect octahedral cleavage. Octahedral cleavage is common for semiconductors. Diamond also has octahedral cleavage.
  *Dodecahedral cleavage occurs when there are  cleavage planes in a crystal. Sphalerite has dodecahedral cleavage.