Ceylon Sapphire Inclusions

First Published: 7 September 2026

Ceylon Sapphire Inclusions

Explore Ceylon sapphire inclusions in Hyperion, the Lotus Gemology inclusion database. Hyperion contains photomicrographs of inclusions and internal features in natural sapphires from Sri Lanka (Ceylon), documented with information on treatment, lighting conditions, field of view, photographer and published references.

These included hexagonal crystals have inclusions of their own. These are actually sapphire inclusions in sapphire, as shown by their extremely low relief. In darkfield they are hard to distinguish from the surrounding corundum, but in crossed polars it’s apparent that they are different crystals.
Gems in gems. When we saw this green crystal inside a blue sapphire from Sri Lanka, we were curious what material it could be. Micro raman analysis confirmed that it is a green spinel.
Orange staining stands out against the body color of this blue sapphire. If a stone like this is heated, the staining is likely to turn a darker reddish color.
Heat treatment of this pink sapphire has caused small negative crystal inclusions to burst, creating shiny discoid fractures around the crystals.
Angular zoned chalky fluorescence like this is a tell-tale sign of heat treatment.
Angular zoned chalky fluorescence like this is a tell-tale sign of heat treatment.
Looking at this image, it’s easy to see why gemologists use the term “fingerprint” to describe partially healed fissures.
This untreated Ceylon sapphire showed an unusual inclusion in the form of a small transparent crystal with two black grains embedded in it. Surrounding this was a flat fissure with a reddish color in transmitted light. It is possible that this is a zircon crystal with embedded uraninite and the reddish stain in the fissure is due to radiation from the zircon/uraninite.
A secondary liquid inclusion in an untreated Ceylon sapphire. The healing pattern suggests that this fingerprint formed oblique to the c-axis.
A secondary liquid inclusion explodes with color when lit from above. The healing pattern suggests that this fingerprint formed oblique to the c-axis.
Written in stone. A large negative crystal appears to have inscribed a delicate pattern in this untreated sapphire from Sri Lanka.
Melted crystals with circular heat-induced “bubbly” fingerprints and partially dissolved silk in a heated sapphire from Sri Lanka; FOV 2 mm

Ceylon sapphire inclusions may include mineral crystals, rutile silk, healed fissures, fluid inclusions, negative crystals, growth features and other internal features formed during or after crystal growth. Such features are important to gemologists because they can provide evidence useful in identifying sapphire and evaluating a possible Sri Lankan origin.

Ceylon Sapphire Inclusion Photomicrographs

The Hyperion Ceylon sapphire gallery includes microscopic features documented in sapphires from Sri Lanka (Ceylon). Each entry is accompanied by descriptive information and, where available, references to the gemological literature.

What Inclusions Can Reveal About Ceylon Sapphire

Inclusions are an important part of geographic origin determination in sapphire. Their form, composition, orientation and associations can provide evidence that, when considered together with other gemological properties, may support or contradict a Sri Lankan origin.

Hyperion combines inclusion photomicrography with supporting gemological information so that individual features can be compared with documented examples from Ceylon sapphires.

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.

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