Heated Sapphire Inclusions

First Published: 7 September 2026

Heated Sapphire Inclusions

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

Iridescent fissures around small crystals create a floral motif in this heated sapphire.
Streams of fine particles zig-zag across this heated sapphire.
This bright orange sapphire shows no evidence of heat treatment in the microscope, but the chalky zoned shortwave ultraviolet fluorescence quickly unmasks the fact that the stone had been heated.
This bright orange sapphire shows no evidence of heat treatment in the microscope, but the chalky zoned shortwave ultraviolet fluorescence quickly unmasks the fact that the stone had been heated.
Angular zoned chalky shortwave fluorescent reaction, indicative of heat treatment.
Chalky shortwave fluorescence is characteristic of heated sapphire.
Iridescent fissures around small crystals create a floral motif in this heated sapphire.
A sharply zoned angular particle cloud creates a striking geometric shape next to a large glassy discoid in this heated Sri Lanka sapphire.
This Burmese pink sapphire has an unusual feature: a drilled hole that extends from the surface into a crystal. We suspect this may have been done to clear out any debris inside the crystal with acid cleaning, making the crystal less noticeable.
Iridescent discoids are reminiscent of flower petals around tiny crystals in this basalt related sapphire.
When viewed with dark-field illumination, the glassy tension halos around each monazite crystal are more distinct.
Brown monazite crystals are sometimes found in sapphires from Madagascar’s Ilakaka region. In this gem one can see glassy tension halos around each, indicating that the gem was subjected to low temperature (less than 1400°C) heat treatment.

Heat treatment can alter inclusions and other internal features in sapphire. Changes may include modification or dissolution of rutile silk, alteration of mineral crystals, decrepitation of fluid inclusions, changes to healed fissures and the formation of heat-related features. Such evidence can be important in determining whether a sapphire has been heated.

Heated Sapphire Inclusion Photomicrographs

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

What Inclusions Can Reveal About Heat Treatment

Microscopic examination is an important part of detecting heat treatment in sapphire. The condition of mineral inclusions, rutile silk, fissures and other internal features can provide evidence of exposure to elevated temperatures. These features are evaluated together with other gemological observations when determining treatment status.

Hyperion combines inclusion photomicrography with supporting gemological information so that heat-related features can be compared with documented examples in treated 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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