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.

This blocky white crystal was found breaking the surface in a pink sapphire from Madagascar’s Ilakaka region collected at the mines by Lotus Gemology’s Richard Hughes in 2005. Using our micro Raman unit to analyze it, we were pleasantly surprised to discover that it was andalusite. To the best of our knowledge, this is the first time andalusite has been discovered as an inclusion in corundum.
This heat-treated blue sapphire from Sri Lanka featured a corundum crystal included in the sapphire that was cut through on the surface. When viewed between crossed polars, the corundum crystal is brilliantly silhouetted against a dark background.
This heat-treated blue sapphire from Sri Lanka featured a corundum crystal included in the sapphire that was cut through on the surface.
When viewed in shortwave UV illumination, chalky angular zoned clouds of particles become evident. This is a clear sign of heat treatment.
When viewed in shortwave UV illumination, chalky angular zoned clouds of particles become evident. This is a clear sign of heat treatment.
When viewed in shortwave UV illumination, chalky angular zoned clouds of particles become evident. This is a clear sign of heat treatment.
A euhedral apatite crystal floats within the milky depths of a sapphire from Madagascar. The apatite was identified by micro Raman. Note the fine texture and sharp growth zoning, both of which are hallmarks of many Madagascar sapphires.
A small fingerprint in a beryllium diffused sapphire. Diffused stones are heat treated at a high temperature.
The appearance of a glassy area and the frosty melted crystal here provide evidence that this sapphire was heated to a high temperature. Further testing confirmed that this sapphire was beryllium diffused.
When examined between crossed polars two twin planes can be easily spotted in this sapphire.
Shiny, glassy discoids and frosted crystals display clear evidence that this sapphire was heated.
A transparent brown phlogopite mica crystal is nestled within this untreated sapphire. Mica is an inclusion commonly found in sapphires from a variety of origins.

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