A large birefringent missile takes flight within this sapphire from Sri Lanka.
Natural Sapphire • Sri Lanka (Ceylon) • Enhancements: None Detected (None) • Lighting Conditions: Diffuse Light Field + Crossed PolarsPhotographer: Richard W. Hughes • Image Number: A-001-3089-1 • Date Posted: 05 November 2015
Hughes, R.W. (1997) Ruby & Sapphire. Boulder, CO, RWH Publishing, 512 pp.; RWHL*.
Gübelin, E.J. and Koivula, J.I. (2005) Photoatlas of Inclusions in Gemstones, Volume 3. Basel, Switzerland, Opinio Publishers, 672 pp.; RWHL*.
Negative crystals in sapphires from Sri Lanka frequently contain trapped daughter crystals within their liquid carbon dioxide fillings. Hexagonal graphite flakes are common, as are slender diaspore needles. In this image, the stone is examined between parallel polars and as it is turned, the tiny diaspore needles become iridescent, thus demonstrating their doubly refractive solid nature.
Natural Sapphire • Sri Lanka (Ceylon) • Enhancements: None Detected (None) • Lighting Conditions: Diffuse Light Field + Parallel PolarsPhotographer: Richard W. Hughes • Image Number: A-001-3085-1 • Date Posted: 05 November 2015
Koivula, J.I. (1986) Carbon dioxide fluid inclusions as proof of natural-colored corundum. Gems & Gemology, Vol. 22, No. 3, pp. 152–155; RWHL*.
Yellow epigenetic limonite stains within a fissure of a sapphire from Sri Lanka. These suggest the stone has not undergone heat treatment, for at just a few hundred degrees centigrade the limonite will convert to reddish hematite.
Natural Sapphire • Sri Lanka (Ceylon) • Enhancements: None Detected (None) • Lighting Conditions: Dark FieldPhotographer: Richard W. Hughes • Image Number: A-001-3087-1 • Date Posted: 05 November 2015
Koivua, J.I. (2013) Useful visual clue indicating corundum heat treatment. Gems & Gemology, Vol. 49, No. 3, Fall, pp. 160–161; RWHL*.
The small dots are gas bubbles showing blue color concentrations. Gas bubbles are a common feature in Verneuil synthetic corundum.
Synthetic Sapphire • Verneuil • Enhancements: None Detected (None) • Lighting Conditions: Dark FieldPhotographer: E. Billie Hughes • Image Number: A-001-3112-1 • Date Posted: 06 November 2015
Hughes, R.W. and Koivula, J. (2005) Dangerous curves: Verneuil synthetic corundum. Bangkok, Lotus Gemology; RWHL.
Curved growth lines and small gas bubbles are visible in this Verneuil synthetic sapphire. The curved lines are a diagnostic feature of Verneuil synthetic corundum. Note that the facets have some rough areas, an indicator that a stone was hastily polished.
Synthetic Sapphire • Verneuil • Enhancements: None Detected (None) • Lighting Conditions: Diffuse Light Field (Transmitted Light)Photographer: E. Billie Hughes • Image Number: A-001-3111-2 • Date Posted: 06 November 2015
Curved growth lines are visible in this Verneuil synthetic sapphire when immersed in methylene iodide. These curved lines are a diagnostic feature of Verneuil synthetic corundum.
Synthetic Sapphire • Verneuil • Enhancements: None Detected (None) • Lighting Conditions: Diffuse Light Field + ImmersionPhotographer: E. Billie Hughes • Image Number: A-001-3111-1 • Date Posted: 06 November 2015
Thin film inclusions in the basal plane of a Thai/Cambodian ruby.
Natural Ruby • Thailand/Cambodia • Enhancements: Heat (H) • Lighting Conditions: Fiber Optic: Diffuse ObliquePhotographer: E. Billie Hughes • Image Number: A-001-3076-7 • Date Posted: 05 November 2015
Natural Ruby • Thailand/Cambodia • Enhancements: Heat (H) • Lighting Conditions: Fiber Optic: Diffuse ObliquePhotographer: E. Billie Hughes • Image Number: A-001-3076-6 • Date Posted: 05 November 2015
Natural Ruby • Thailand/Cambodia • Enhancements: Heat (H) • Lighting Conditions: Fiber Optic: Diffuse ObliquePhotographer: E. Billie Hughes • Image Number: A-001-3076-5 • Date Posted: 05 November 2015
A melted crystal and surrounding fingerprint form a "Saturn inclusion" in this heated ruby from the Thai/Cambodian border. Thin films are also seen in the background and lie in the plane of the basal pinacoid.
Natural Ruby • Thailand/Cambodia • Enhancements: Heat (H) • Lighting Conditions: Fiber Optic: Diffuse ObliquePhotographer: E. Billie Hughes • Image Number: A-001-3076-4 • Date Posted: 05 November 2015
Natural Ruby • Thailand/Cambodia • Enhancements: Heat (H) • Lighting Conditions: Fiber Optic: Diffuse ObliquePhotographer: E. Billie Hughes • Image Number: A-001-3076-2 • Date Posted: 05 November 2015
A melted crystal with a frosted surface surrounded by a fingerprint with melted channels. Often known as a "saturn inclusions,” these melted crystals are common in heated Thai ruby.
Natural Ruby • Thailand/Cambodia • Enhancements: Heat (H) • Lighting Conditions: Dark Field + Oblique Fiber OpticPhotographer: E. Billie Hughes • Image Number: A-001-3076-1 • Date Posted: 05 November 2015