Rhombohedral

Bravais lattice
Rhombohedral

Different structures

• 
  D5₁ (α-Al₂O₃, α-Fe₂O₃)
• 
  D5₁ (same structure, different description)

Crystal structures: triclinic - monoclinic - orthorhombic - hexagonal - rhombohedral - tetragonal - cubic