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 circular heat-induced “bubbly” fingerprints and partially dissolved silk in a heated sapphire from Sri Lanka; FOV 2 mm
Negative crystal containing birefringent diaspore needles needles and a small graphite plate; unheated Sri Lanka sapphire
Dark blue color zones such as this surrounded by milky areas are a common feature of Madagascar sapphire from the Ilakaka region; sometimes these stones are confused with those from Kashmir; FOV 5.5 mm
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.
Angular cloud of particles in sapphire. Such dense “texture clouds” are often a sign of high-temperature heat treatment; FOV~ 7 mm
Sapphires treated with high temperatures and modest pressure (HT+P) sometimes contain ghost-like fingerprints with low relief crystals, when viewed in transmitted light. In crossed polars, these crystals stand out clearly and are birefringent. Using Lotus Gemology’s micro Raman unit, we have identified these crystals as recrystallized corundum.
Sapphires treated with high temperatures and modest pressure (HT+P) sometimes contain ghost-like fingerprints with low relief crystals, when viewed in transmitted light. In crossed polars, these crystals stand out clearly and are birefringent. Using Lotus Gemology’s micro Raman unit, we have identified these crystals as recrystallized corundum.
Elongated rods of what is probably amphibole display rainbow interference colors when observed between crossed polars. The interference colors prove the needles are doubly refractive.
Written in stone. A large negative crystal appears to have inscribed a delicate pattern in this untreated sapphire from Sri Lanka.
Thin films of liquid light up the interior of a trapiche sapphire.

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.