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.
“Ink spot internal diffusion” surrounding partially resorbed rutile silk indicates that this stone has been heated. During treatment, the rutile dissolves, sending titanium into solution, thus coloring the stone blue around the silk.
Natural Sapphire •
Sri Lanka (Ceylon) •
Enhancements:
Heat (H) •
Lighting Conditions:
Diffuse Light Field (Transmitted Light)
Photographer:
Patharaphum Sudprasert •
Image Number:
A-002-1566-1
Koivula, J.I. (1987) Internal diffusion. Journal of Gemmology, Vol. 20, No. 7/8, pp. 474–477; RWHL*.
Triangular growth zoning in a Madagascar sapphire. Milky regions contrasting with deep blue zones are common in Madagascar sapphire.
Natural Sapphire •
Madagascar •
Enhancements:
Heat (H) •
Lighting Conditions:
Dark Field + Oblique Fiber Optic
Photographer:
Patharaphum Sudprasert •
Image Number:
A-001-9419-1
These melted snowball crystals with glassy discoids provide evidence of heat treatment in this Sri Lanka sapphire.
Natural Sapphire •
Sri Lanka (Ceylon) •
Enhancements:
Heat (H) •
Lighting Conditions:
Fiber Optic: Diffuse Oblique
Photographer:
E. Billie Hughes •
Image Number:
A-001-7683-2
These melted snowball crystals with glassy discoids provide evidence of heat treatment in this Sri Lanka sapphire.
Natural Sapphire •
Sri Lanka (Ceylon) •
Enhancements:
Heat (H) •
Lighting Conditions:
Fiber Optic: Diffuse Oblique
Photographer:
E. Billie Hughes •
Image Number:
A-001-7683-1
Melted crystals surrounded by heat-altered fingerprints in a heat-treated Madagascar sapphire.
Natural Sapphire •
Madagascar •
Enhancements:
Heat (H) •
Lighting Conditions:
Diffuse Light Field + Fiber Optic
Photographer:
Patharaphum Sudprasert •
Image Number:
A-001-8832-1
Hughes, R.W. (1997) Ruby & Sapphire. Boulder, CO, RWH Publishing, 512 pp.; RWHL*.
A frozen gas bubble shines in a negative crystal in this heated basaltic sapphire. When illuminated from some angles, there is a visible fissure surrounding the crystal, providing further evidence of heat treatment.
Natural Sapphire •
Nigeria •
Enhancements:
Heat (H) •
Lighting Conditions:
Fiber Optic: Diffuse Oblique
Photographer:
E. Billie Hughes •
Image Number:
A-001-7505-6
A frozen gas bubble shines in a negative crystal in this heated basaltic sapphire.
Natural Sapphire •
Nigeria •
Enhancements:
Heat (H) •
Lighting Conditions:
Fiber Optic: Transmitted
Photographer:
E. Billie Hughes •
Image Number:
A-001-7505-5
Frozen gas bubble in a melted negative crystal in basaltic sapphire.
Natural Sapphire •
Nigeria •
Enhancements:
Heat (H) •
Lighting Conditions:
Diffuse Light Field (Transmitted Light)
Photographer:
Patharaphum Sudprasert •
Image Number:
A-001-6887-1
Transparent birefringent crystals and heat-altered fingerprints in a sapphire of unknown origin.
Natural Sapphire •
Not Determinable •
Enhancements:
Heat (H) •
Lighting Conditions:
Diffuse Light Field + Crossed Polars
Photographer:
Richard W. Hughes •
Image Number:
A-001-6792-1
The surfaces of these negative crystals are glossy and smooth, showing signs of heating in this Sri Lankan sapphire.
Natural Sapphire •
Sri Lanka (Ceylon) •
Enhancements:
Heat (H) •
Lighting Conditions:
Dark Field + Diffuse Fiber Optic
Photographer:
E. Billie Hughes •
Image Number:
A-001-6480-1
An iridescent fissure surrounds a small crystal in this basaltic sapphire from Bo Ploi, Thailand. When an included crystal such as this is heated, it expands, producing pressure on the host. The easiest release of that pressure is generally in the basal plane, producing a flat “discoid” fissure such as this.
Natural Sapphire •
Thailand (Siam); Bo Ploi •
Enhancements:
Heat (H) •
Lighting Conditions:
Fiber Optic: Oblique
Photographer:
Richard W. Hughes •
Image Number:
A-001-5761-1
These long growth tubes with glassy areas show clear signs of heat alteration.
Natural Sapphire •
Madagascar •
Enhancements:
Heat (H) •
Lighting Conditions:
Dark Field
Photographer:
E. Billie Hughes •
Image Number:
A-001-5414-1
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.
