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.

When chalky fluorescence is seen in shortwave UV light, it generally indicates a sapphire has been heat treated. The exception is a superficial chalky patch such as that seen here.
A cavity in sapphire filled with debris and several bubbles; this cavity is open to the surface and appears to be filled with dopping varnish or a resin. FOV ~4.5 mm
Small crystals with decolorized areas around growth tubes cut through on the surface. The growth tubes have apparently drawn titanium out of solid solution in the sapphire, thus cannibalizing the color.
Melted crystals with circular heat-induced “bubbly” fingerprints and partially dissolved silk in a heated sapphire from Sri Lanka; FOV 2 mm
Melted crystal with frozen bubble in sapphire. When a gem is heated, included crystals may melt and cool into a glass. Because the glass takes up less volume than the previous solid crystal, a contraction bubble forms in the glass; FOV ~2.5 mm
Fingerprint in untreated Mogok sapphire; note the vertical striations visible on the liquid channels; FOV 4 mm
Negative crystal containing birefringent diaspore needles needles and a small graphite plate; unheated Sri Lanka sapphire
Apatite crystal (ID’d with Lotus Gemology’s micro Raman) in sapphire; FOV 3 mm
Rose channels (formerly thought to be boehmite needles) forming Star of David pattern in a flux healed Greenland pink sapphire. FOV ~2.5 mm
Rose channels (formerly thought to be boehmite needles) forming Star of David pattern in a flux healed Greenland pink sapphire.
Unusual birefringent crystals in a low-relief partially healed fissure in a sapphire treated with high-temperature heat plus modest pressure (HT+P). When tested with Lotus Gemology’s microraman, they proved to be corundum. It is thought that they crystallized during the treatment process. FOV 2 mm
Unusual birefringent crystals in a low-relief partially healed fissure in a sapphire treated with high-temperature heat plus modest pressure (HT+P). When tested with Lotus Gemology’s microraman, they proved to be corundum. It is thought that they crystallized during the treatment process. FOV 2 mm

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