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.

These included hexagonal crystals have inclusions of their own. These are actually sapphire inclusions in sapphire, as shown by their extremely low relief. In darkfield they are hard to distinguish from the surrounding corundum, but in crossed polars it’s apparent that they are different crystals.
An elongated crystal in this sapphire was identified as grandidierite with micro Raman. Here in crossed polars we can see it display rainbow interference colors.
An elongated crystal in this sapphire was identified as grandidierite with micro Raman.
Red pyrochlore crystals like this one, which was identified with microraman spectroscopy, are a common inclusion in basalt-related sapphire.
Gems in gems. When we saw this green crystal inside a blue sapphire from Sri Lanka, we were curious what material it could be. Micro raman analysis confirmed that it is a green spinel.
Orange staining stands out against the body color of this blue sapphire. If a stone like this is heated, the staining is likely to turn a darker reddish color.
Heat treatment of this pink sapphire has caused small negative crystal inclusions to burst, creating shiny discoid fractures around the crystals.
Angular zoned chalky fluorescence like this is a tell-tale sign of heat treatment.
Angular zoned chalky fluorescence like this is a tell-tale sign of heat treatment.
Seeing the chalky hexagonal banding in shortwave UV light reveals that this sapphire from Burma was heated. Photo taken with M&A Instruments Deep-UV Fluorescence system.
Seeing the chalky hexagonal banding in shortwave UV light reveals that this sapphire from Burma was heated. Photo taken with M&A Instruments Deep-UV Fluorescence system.
Looking at this image, it’s easy to see why gemologists use the term “fingerprint” to describe partially healed fissures.

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