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.

Melted crystals with a frosted surface, surrounded by heat-altered fingerprints in a heat-treated sapphire from Sri Lanka. Note the hexagonal symmetry of the fingerprint, which shows that it lies in the basal plane.
A heat-altered fingerprint at the culet of a heat-treated sapphire from Sri Lanka. Note the small microfractures and discoids that result from explosion of the individual negative crystal channels that make up the fingerprint.
A small cluster of transparent zircon crystals with no signs of heat alteration are a welcome sight in this unheated Madagascar sapphire. Should the gem have been heat treated at temperatures typical for blue sapphire, these zircon crystals would have become cloudy and whitish and the small tension fractures around them would have begun to heal.
Four titanium lattice-diffused sapphires surround a natural untreated sapphire. The characteristic dark girdles and highlighted facet junctions of the lattice-diffused sapphires are readily apparent.
The yellow core of this Sri Lankan sapphire fluoresces orange when illuminated by a strong fiber-optic light.
This iridescent discoid around a melted crystal demonstrates that this sapphire has been heat treated.
“Crop circles” in a heated sapphire from Sri Lanka. These types of inclusions have been associated with, but are not limited to, beryllium-treated blue sapphires.
Iron-rich “hairy” silk is often seen in green zones just below the basal pinacoid surfaces of yellow sapphires from Chanthaburi, Thailand.
Fingerprints betray the underlying atomic symmetry. In this case, this iridescent fingerprint lies along a prism face, as demonstrated by its rectilinear form.
Melted crystals with frozen gas bubbles litter the interior of this heated sapphire from Mambilla, Nigeria.
Exsolved rutile silk is one of the classic inclusions found in Mogok sapphires.
Exsolved rutile silk opens a window into the heart of this unheated Mogok 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.

Search the Complete Hyperion Database