Star Sapphire Inclusions

First Published: 7 September 2026

Star Sapphire Inclusions

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

This Burmese sapphire was diffused with titanium to induce both a blue color and a star. One can see bleeding of blue color into both surface openings and heavy heat alteration of fingerprints, creating a “drippy” appearance.
Like balloons on a string, these unusual crystals of what may be apatite with attached growth tubes, along with a negative crystal, enrich the interior of this purple star sapphire from Sri Lanka.
This long green crystal of what is probably pargasite is an unusual guess in sapphire from Burma’s Mogok Stone Tract.
A single twin plane stands out in brilliant contrast when examined between crossed polars in this star sapphire from Sri Lanka.
Otherworldly birefringent crystals float above a twin plane in a sapphire from Sri Lanka.
Otherworldly birefringent crystals float above a twin plane in a sapphire from Sri Lanka.
Balloons on a string. Unusual crystals of what may be apatite with attached growth tube strings in a purple star sapphire from Sri Lanka.
Unusual crystals of what may be apatite with attached growth tubes in a purple star sapphire from Sri Lanka.
Iron-rich silk in a black star sapphire from Chanthaburi, Thailand.
Basal parting on the back of a black star sapphire from Chanthaburi, Thailand. Exsolution of iron-rich inclusions in the basal plane produce mechanical weakness.
Dark brown exsolved plates are seen within one area of this golden sheen sapphire from Kenya.

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Star sapphire inclusions may include oriented rutile silk, mineral crystals, healed fissures, fluid inclusions, growth zoning and other features formed during or after crystal growth. Of particular importance are oriented inclusions capable of producing asterism when the stone is cut with the appropriate orientation.

Star Sapphire Inclusion Photomicrographs

The Hyperion star sapphire gallery includes microscopic features documented in natural star sapphires from deposits around the world. Each entry is accompanied by descriptive information and, where available, references to the gemological literature.

What Inclusions Can Reveal About Star Sapphire

Inclusions are fundamental to the study of star sapphire because asterism results from light reflected by oriented internal features. Microscopic examination can help reveal the nature and orientation of these features, distinguish natural asterism from some artificial effects, recognize evidence of treatment and provide information relevant to geographic origin.

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