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.

This sapphire contains fine, milky texture clouds that create a “velvety” glow.
Appearing like stardust against the night sky, streams of tiny particles can be seen in the interior of this blue sapphire.
The high temperature that this blue sapphire from Madagascar was exposed to during beryllium diffusion treatment melted part of the girdle of the stone. Also, in the lower right corner of the photo is the tiny ablation spot that the LIBS created in order to detect the beryllium.
The rose channels in this Madagascar blue sapphire have melted and begun to “neck down” due to the high temperature it was exposed to during beryllium diffusion treatment.
This high temperature heat-treated blue sapphire from a basalt-related source displays zoned internal diffusion. The high temperature (usually above 1600˚C) causes the rutile needles to dissolve and release titanium into the host sapphire, the titanium pairs with the iron in the stone and this creates blue color around the rutile silk remnants.
Fine needles of rutile "silk" create a dazzling display in this untreated sapphire. In this case, the silk is responsible for the asterism (star) effect in the stone.
This cornflower blue sapphire features fine unaltered rutile silk needles in intersecting planes; a common sight in sapphires from Myanmar (Burma).
Some of the small particles in this sapphire are surrounded blue color concentrations. Often termed “internal diffusion,” this occurs when titanium from rutile dissolves (enters into solid solution) into the surrounding sapphire as a result of heat treatment. Once in solid solution, the Ti atoms combine with Fe atoms, producing an intervalence charge transfer that absorbs light.
A pair of tiny crystals surrounded by bubbly fingerprints provide evidence that this sapphire has been heated.
High temperature heat treatment melted the surface of this sapphire, resulting in recrystallized corundum at and just below the surface.
Fine channels form a beautiful partially healed fissure in this sapphire, creating a unique “fingerprint” for the stone.
Zoned particles in Kashmir sapphire.

Search the Complete Hyperion Database

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.