Treated Sapphire Inclusions

First Published: 7 September 2026

Treated Sapphire Inclusions

Explore treated sapphire inclusions in Hyperion, the Lotus Gemology inclusion database. Hyperion contains photomicrographs of inclusions and internal features in natural sapphires that have undergone treatment, documented with information on geographic origin, treatment, lighting conditions, field of view, photographer and published references.

A small crystal with an iridescent thin-film decrepitation halo surrounding it. When a crystal is heated (either by a magma or artificially by human intervention), it expands. Tension is often relieved by a fissure in the weakest direction, the basal plane.
A small crystal with an iridescent thin-film decrepitation halo surrounding it. When a crystal is heated (either by a magma or artificially by human intervention), it expands. Tension is often relieved by a fissure in the weakest direction, the basal plane.
Small spotted platelets spread across the blue skies of this Madagascar sapphire.
This heated sapphire shows signs of treatment with these shallow, heat-altered fingerprints.
A melted crystal with a frozen gas bubble inside is suspended over a backdrop of partially dissolved silk which displays “inkspot” internal diffusion.
Orange crystals seem to float against a midnight blue sky, with angular growth zoning visible in the background, in this sapphire from New South Wales, Australia. Specimen courtesy of Terrence Coldham.
This elongated cavity is starting to show the signs of melting as a result of heat treatment as the edge become rounded.
Tiny melted crystals and heat-altered fingerprints suggest that this sapphire has undergone heat treatment.
“Punsiri” zoning in a heated blue sapphire.
“Deep” titanium-diffused preform sliced open andn polished to reveal the depth of color penetration. Note that much of the color layer will be removed during polishing. Despite claims by manufacturers, the so-called “deep diffusion” process showed no more color penetration than that claimed in the original Linde patents, i.e. up to 0.50 mm.
This lattice diffusion treated, heated sapphire shows blue color concentrations along the facet edges when immersed in diiodomethane.
During heat treatment, primary rutile crystals leech titanium into the surrounding corundum, coloring it blue. This process is termed “internal diffusion.”

Treatment can alter existing inclusions and produce new microscopic features in sapphire. These may include changes to mineral inclusions, altered rutile silk, tension fractures, healed fissures, residues and other features associated with heating, diffusion, fissure filling and other treatment processes.

Treated Sapphire Inclusion Photomicrographs

The Hyperion treated sapphire gallery includes microscopic features documented in natural sapphires subjected to treatment. Each entry identifies the recorded treatment and is accompanied by descriptive information and, where available, references to the gemological literature.

What Inclusions Can Reveal About Sapphire Treatment

Microscopic examination is an important part of detecting treatment in sapphire. The appearance and alteration of inclusions, fractures and growth features can provide evidence of treatment and, in some cases, information about the processes to which a sapphire has been subjected.

Hyperion combines inclusion photomicrography with supporting gemological information so that treatment-related features can be compared with documented examples in natural sapphire.

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