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.

An iridescent fissure in a sapphire from Tanzania’s Umba Valley.
Basal parting on the back of a black star sapphire from Chanthaburi, Thailand. Exsolution of iron-rich inclusions in the basal plane produce mechanical weakness.
A heat-induced discoid inclusion in a heat-treated sapphire from Sri Lanka.
Heat-altered fingerprints in a heat-treated Ceylon sapphire. Close examination reveals microscopic fractures around each negative crystal, due to the heat treatment.
Uniaxial interference figure in blue sapphire.
When a silky sapphire is heated to a high enough temperature, titanium from the rutile silk is forced into solid solution, coloring the stone blue. But the silk may also contain other elements that cannot dissolve into sapphire so readily, leaving behind silk “skeletons,” as shown here.
Birefringent crystal in transmitted light. If examined between crossed polars, it will reveal its doubly refractive nature.
A transparent birefringent crystal reveals its doubly refractive nature when examined between crossed polars in this untreated sapphire from Sri Lanka.
A lovely example of a fingerprint in an unheated sapphire from Sri Lanka.
Negative crystal with a carbon dioxide bubble and graphite crystal in an unheated Sri Lanka sapphire. Such inclusions cannot tolerate heat treatment and thus are proof of natural, unheated origin.
A crystal cut through on surface is strikingly iridescent when examined between crossed polars in this untreated sapphire from Sri Lanka.
Iron-rich exsolved plates decorate the interior of a golden-sheen sapphire from Kenya.

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.