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.

Tiny red uranium pyrochlore crystals glow in this sapphire from Pailin, Cambodia. These crystals are a diagnostic inclusion for magmatic sapphires.
This transparent crystal was an obstacle to this sapphire’s growth, creating a “comet trail” stream of fine particles behind it. This example is in a Pailin sapphire.
A tiny red uranium pyrochlore octahedron glows in this sapphire from Pailin, Cambodia. These pyrochlore crystals are a diagnostic inclusion for magmatic sapphires.
These droplet-like surface markings may superficially look like water or oil, but they cannot be wiped or scraped off. They are actually spall marks, a result of heat treatment that affects the surface of the stone. Often a heated stone will be repolished to remove such markings.
Many crystals contain shallow fissures on their surfaces. In sapphires from Sri Lanka, Myanmar and Madagascar, these fissures often contain yellow stains. High-temperature heating not only destroys the yellow stains, but begins a process of healing, where the fissures turn white and start forming fingerprints.
Dense clouds of exsolved titanium-bearing minerals have created the fanciful scenery within this untreated sapphire from Madagascar. As the crystal cooled these growing clouds sucked titanium from the surrounding sapphire, thus robbing it of an essential chromophore. The result is decolorized zones surrounding the clouds, a process dubbed “chromophore cannibalization” by microphotographic maestro John Koivula.
Orange primary rutile crystals stand out against a backdrop of exsolved particles in a hexagonal pattern in this Montana sapphire.
Iridescent fissures light up the interior of this heat-treated Ceylon sapphire in a spectacular display of colors.
Sharp angular growth zoning, which is typical in Madagascar sapphire. This can help separate natural stones from Verneuil flame fusion synthetics, which have curved color banding.
These fine parallel lines show the sharp angular growth zoning typical in Madagascar sapphire. These lines can be distinguished from polishing lines because they cross several facets.
A long, orange-stained growth tube pierces this Madagascar sapphire. These fine growth tubes are a common feature in sapphire from Madagascar.
A melted “snowball” crystal is surrounded by a fingerprint showing many small bubbles, a sign of heat alteration. This inclusion is typically found in heated Sri Lankan sapphire.

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.

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