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.

Like a terraced mountain, this large negative crystal rises in the center of an untreated padparadscha sapphire from Sri Lanka.
A delightful sight. This pinkish purple sapphire from Serendib features a lovely iridescent fingerprint, its structure mimicing the underlying atomic pattern of its host.
Exsolved rutile silk lights up the interior of this natural blue sapphire from Sri Lanka. It is these inclusions that give rise to the stars in cabochon-cut stones.
The clear, undamaged, euhedral form of this crystal, suspended in its sapphire host, provides evidence that the stone is unheated.
Like Mother Nature’s snow globe, Sri Lankan sapphire often has negative crystals containing other inclusions. In this example we can see small diaspore needles and black graphite flakes inside the cavities.
When a rutile-silk containing sapphire is heated, titanium from the rutile dissolves into the surrounding sapphire. Once in solid solution, the titanium reacts with iron, creating a blue color. The result is tiny blue halos surrounding the remnants of the rutile silk, a process dubbed “inkspot internal diffusion” by John Koivula. This partially dissolved silk with blue color concentrations is a clear sign that the sapphire was heated.
A melted “snowball” crystal is surrounded by a fingerprint showing many small bubbles, a sign of heat alteration. This inclusion is typically found in heated Sri Lankan sapphire.
A melted “snowball” crystal is ensconced in heat-altered fingerprints in this heated sapphire from Sri Lanka. Such “snowballs” and bubbly fingerprints are typical of stones heated at high temperatures.
Small, blocky black uraninite crystals and rounded, transparent zircon crystals such as these are commonly found in Sri Lankan sapphire. While at first their shiny halos may seem like evidence of heat treatment, they can actually occur naturally, as in this stone. The undissolved rutile silk needles in this stone demonstrate that it has not been heated at a high temperature.
A small black uraninite crystal with shiny fissures around it. While at first this may seem like evidence of heat treatment, these halos can actually occur naturally, as in this stone. The undissolved rutile silk needles in this stone demonstrate that it has not been heated at a high temperature.
Small black uraninite crystals with shiny fissures around them in a Sri Lankan sapphire. While at first these may seem like evidence of heat treatment, these halos can actually occur naturally, as in this stone. The undissolved rutile silk needles in this stone demonstrate that it has not been heated at a high temperature.
These droplet-like surface markings may superficially look like water or oil, but they cannot be wiped or scraped off. They are actually spall marks, a result of heat treatment that affects the surface of the stone. Often a heated stone will be repolished to remove such markings.

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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.