Inclusions Typically Found in Sapphires
Cavities : Voids or holes that extend from surface of a gemstone to interior
Color Zoning : Areas or bands of alternating color in a gemstone.
Halo or Fractures : Oval or circular fractures surroundinfg a solid or liquid inclusion. These are formed from stress due to radioactive decay of tiny zircons .
Included Crystal : Light, dark,transparent or opaque mineral trapped inside a gemstone .In sapphire you can find minute crystal of hematite,zircon,spinel,calcite and mica.
Liquid Inclusion: Liquid filled spaces within a gemstone.