Sapphire Inclusions

First Published: 7 September 2026

Sapphire Inclusions

Explore sapphire inclusions in Hyperion, the Lotus Gemology inclusion database. Hyperion contains photomicrographs of inclusions and internal features in natural sapphire, documented with information on geographic origin, treatment, lighting conditions, field of view, photographer and published references.

A series of thin-film decrepitation halos decorates the interior of this blue sapphire.
A series of thin-film decrepitation halos decorates the interior of this blue sapphire.
The glassy appearance and melted channels in this fingerprint, or partially healed fissure, are signs that this blue sapphire was heat treated.
A small, transparent crystal inside this sapphire shows signs of heat treatment. Notice how the small fingerprint around it has a drippy, melted appearance.
The angular chalky reaction, observable with short wave illumination, provides clear evidence that this blue sapphire was heated.
Sharp angular growth zoning and a series of thin-film decrepitation halos, which look brown in this lighting condition, stand out in this blue sapphire.
A series of thin-film decrepitation halos decorates the interior of this blue sapphire.
A series of thin-film decrepitation halos decorates the interior of this blue sapphire. We can see that light reflects off them at the same angle.
This violet sapphire contained many interesting inclusions, including this rounded metallic crystal. Although we were not able to confirm its identity with Raman spectroscopy, from its appearance we can infer that it’s likely a sulphide.
The violet sapphire pictured here contained many brown, transparent crystals. These were identified as phlogopite mica with Raman spectroscopy.
When we were testing this blue sapphire, the yellow crystal pictured here stood out immediately. Analysis with micro Raman revealed that it is phlogopite mica.
These small black crystals, likely uraninite, are surrounded by an unusual red halo. They are set against a fine fingerprint with small negative crystals that show no signs of heat damage.

Sapphire inclusions may include mineral crystals, rutile silk, healed fissures, fluid inclusions, negative crystals, color zoning and other features formed during or after crystal growth. Such features are important to gemologists because they can provide evidence useful in identifying sapphire, understanding its geological history, recognizing treatment and, in some cases, determining geographic origin.

Sapphire Inclusion Photomicrographs

The Hyperion sapphire gallery includes microscopic features found in sapphires from major deposits around the world. Each entry is accompanied by descriptive information and, where available, references to the gemological literature.

What Inclusions Can Reveal About Sapphire

Inclusions are an important part of sapphire identification. Their form, composition, orientation and alteration can help gemologists distinguish natural sapphire from synthetic material, recognize evidence of heat treatment, and study the geological environment in which the sapphire formed.

Hyperion combines inclusion photomicrography with supporting gemological information so that individual features can be compared with documented examples from known sapphire deposits.

About Hyperion

Hyperion is the Lotus Gemology searchable inclusion database. It allows users to browse gemstone inclusions by gem type, geographic origin, treatment and keyword.

Search the Complete Hyperion Database