Rutile silk, guest crystals and liquid fingerprints in an unheated blue sapphire from Mogok.

Rounded calcite guest crystals in an unheated blue sapphire from Mogok.

Liquid fingerprint (secondary) inclusion in an unheated Mogok blue sapphire.

Guest crystals in an untreated Burmese sapphire.

Liquid fingerprints and guest crystals in an unheated Mogok blue sapphire.

 Note the two-phase liquid inclusions containing a gas bubble in the centre

 of the picture.

Guest crystals and rutile silk in unheated blue sapphire from Mogok.

 A multitude of tiny guest crystals in an unheated Burmese blue sapphire.

Guest crystals and rutile silk in an unheated Burmese blue sapphire.

Rutile silk in an unheated blue sapphire from Sri Lanka. The interference

 colours in this picture can be seen when viewing these inclusions with a

 fibre optic light.

Rutile silk in an unheated Sri Lanka blue sapphire. The interference colours

 clearly visible in this picture. If the stone is heated to high temperatures,

 these inclusions will dissolve or partially dissolve and become distorted.

 The interference colours would also no longer be visible.