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Sapphire

The name “sapphire” can also apply to any corundum that’s not ruby red, another corundum variety.

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Madagascar Beauty

This 7.04-ct. oval sapphire is from a new source, the island Madagascar.

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Blue Velvet

Deep, intense, velvety blue describes this sapphire’s color.

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Best in Daylight

Blue sapphire looks best in daylight and fluorescent light.

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Spindle Shape

This spindle-shaped crystal from Sri Lanka weighs 70.10-cts.

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Color Zoning

Blue color distribution in sapphire crystals is often uneven.

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Twinned

There is a second sapphire crystal growing into the larger one.

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Tools

Research

The rectilinear zigzag-patterned fingerprint in this 3.21 ct blue sapphire shows beautiful vibrant colors, indicating a Sri Lankan origin. Photomicrograph by Yuxiao Li; field of view 4.45 mm.
Zigzag Fingerprint in Sri Lankan Sapphire

Fiber-optic illumination reveals rectilinear zigzag-patterned films with vibrant colors in a blue sapphire.

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Figure 1. These exceptional natural yellow sapphires from Madagascar (2.1–2.6 ct) represent both the Fe<sup>3+</sup> chromophore and the trapped hole paired with Fe<sup>3+</sup>. Photo by Ronnakorn Manorotkul/Lotus Gemology; courtesy of GemFever.
Yellow Sapphire: Natural, Heat-Treated, Beryllium-Diffused, and Synthetic

Investigates the various chromophores responsible for color in four types of yellow sapphire.

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This scene of an iron stain and numerous curved lines showing rainbow colors in a fracture resembles a scene from the night sky viewed through a telescope rather than a microscope. Photomicrograph by Charuwan Khowpong; field of view 2.85 mm.
Night Sky in Yellow Sapphire

Fiber-optic light creates a night sky scene in a yellow sapphire from Madagascar.

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This pristine hexagonal platelet of graphite was seen in a pink sapphire from Sri Lanka. Photomicrograph by Jeffrey Hernandez; field of view 1.99 mm.
Pink Sapphire with Graphite Inclusion

A hexagonal platelet of graphite is discovered in a pink sapphire from Sri Lanka.

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Negative crystals arrayed in an arrow-like pattern. Photomicrograph by Suwasan Wongchacree; field of view 1.07 mm.
Arrow-Patterned Negative Crystals in Sapphire

Examination of a sapphire reveals negative crystals arrayed in an arrow-like pattern.

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Figure 1. Top production from Rock Creek from the 2021 mining season, in rough and cut form. The rough stones range from 10.05 to 67.15 ct and the faceted stones from 3.09 to 12.18 ct. The yellow sapphire at top center was named the Yellowstone sapphire and is part of the Somewhere in the Rainbow collection. For the faceted stones, the blue stone on the left and the two blue stones on the bottom are heated, while the others are unheated. Note that one of the rough stones is missing in the faceted stone layout. Photos by Robert Weldon; courtesy of Potentate Mining, LLC.
Gemological Characterization of Montana Sapphire from the Secondary Deposits at Rock Creek, Missouri River, and Dry Cottonwood Creek

Examines the mining history and geological characteristics of the three secondary sapphire deposits in the state of Montana, as well as the properties of these sapphires (unheated and heat-treated).

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Figure 1. Color-calibrated photo of a 0.664 ct pink sapphire from Madagascar before and after irradiation, and after fade test using fiber-optic light for 6 hours. Path length/thickness: 1.514 mm. Photos by Sasithorn Engniwat.
Chromophore Behaviors (Including the 880 nm Absorption Band) in an Irradiated Pink Sapphire

A report showing the preliminary results of a radiation experiment with pink sapphire from Madagascar.

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Figure 1. A 3.02 ct heated purplish pink sapphire measuring 9.57 × 7.74 × 4.55 mm. Photo by Ugo Hennebois.
Heated Purplish Pink Sapphire from Ilakaka (Madagascar) with Colored Monazite Inclusions

Orange-brown monazite inclusions in a purplish pink sapphire are analyzed for evidence of heat treatment.

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Figure 1. The “Seven Sisters” ring in 18K gold with 17 bezel-set diamonds (0.55 carats total) and 22 sapphires ranging in size from 2.5 to 4.0 mm in blue, orange, mandarin, pink, and green (3.15 carats total). Photo by Robert Weldon; courtesy of Sean Hill Designs.
Sean Hill: Exquisite Jewelry Designs

Former university professor Sean Hill shares some of his unique jewelry designs at the GJX show.

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Figure 1. Part of the suite of sapphires studied for this project (weighing 0.23–1.41 ct). Photo by Sasithorn Engniwat; courtesy of Greenland Ruby.
Color Study of Fancy Sapphire from Greenland

The Bangkok laboratory identifies the chromophores responsible for the fancy colors observed in treated sapphire from Aappaluttoq, Greenland.

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