Natural Ruby Inclusions

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

After this ruby grew, it was exposed to high pressure, causing certain planes of atoms to glide into a twinned position. This secondary “polysynthetic” twinning takes place along the rhombohedron faces and is common in many corundums. Twin planes cross at 86.1 and 93.9° angles.
Undissolved rutile silk in the basal plane of this ruby from Montepuez, Mozambique, creates a lovely pattern.
Angular growth zoning is often seen in rubies from Montepuez, Mozambique.
Low iron rubies (and pink and padparadscha sapphires) from localities like Mogok, Mong Hsu (Myanmar) and Sri Lanka will often display chalky zones in shortwave ultraviolet. Here we see an excellent example in a heat-treated ruby from Mong Hsu. This fluorescence is positive proof of heat treatment.
A solidified droplet of glass was found on the surface of this Mozambique ruby, thus suggesting it had been subjected to artificial heat treatment.
This untreated ruby from Tanzania’s Winza mines shows unusual long needle inclusions.
Mozambique rubies contain mixed silk, where part is rutile and part is another mineral. When heated, the non-rutile portion may show breakdown in the form of mottling or bubbles, as seen here.
A mica crystal with a lovely “rosette” inclusion surrounding it creates a secret beauty in this Montepuez (Mozambique) ruby.
Rutile silk (high relief) with daughter crystals (lower relief) at the broad ends is a common feature of Mozambique rubies. Heat treatment often produces a breakdown, creating white spots or bubbles within the daughter crystals, as well as a rim developing on the outside edge, as seen here.
Rutile silk (high relief) with daughter crystals (lower relief) at the broad ends is a common feature of Mozambique rubies. Heat treatment often produces a breakdown, creating white spots or bubbles within the daughter crystals, as well as a rim developing on the outside edge, as seen here.
Rutile silk (high relief) with daughter crystals (lower relief) at the broad ends is a common feature of Mozambique rubies. Heat treatment often produces a breakdown, creating white spots or bubbles within the daughter crystals, as can be seen here.

Natural ruby inclusions may include mineral crystals, rutile silk, healed fissures, fluid inclusions, negative crystals, color zoning and other features formed during or after crystal growth. Such features are important to gemologists because they can provide evidence useful in identifying ruby, understanding its geological history, recognizing treatment and, in some cases, determining geographic origin.

Natural Ruby Inclusion Photomicrographs

The Hyperion natural ruby gallery includes microscopic features found in rubies from major deposits around the world. Each entry is accompanied by descriptive information and, where available, references to the gemological literature.

What Inclusions Can Reveal About Natural Ruby

Inclusions are an important part of ruby identification. Their form, composition, orientation and alteration can help gemologists distinguish natural ruby from synthetic material, recognize evidence of heat treatment, and study the geological environment in which the ruby formed.

Hyperion combines inclusion photomicrography with supporting gemological information so that individual features can be compared with documented examples from known ruby deposits.

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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