Synthetic Gem Materials in the 1980s

Nassau, K.

doi:10.5741/gems.26.1.50

Cited by 13 publications

(8 citation statements)

References 41 publications

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“…Because of the commercial value of beryl, a large number of synthetic samples is permanently present on the market (Koivula et al, 2000). The production of marketable synthetic beryls from hydrothermal growth techniques dates back to the end of 1980s, and the different stones' colourations are obtained using chromophoric dopants such as, for instance, V, Cr, Mn, Fe, Co, Ni and Cu (Koivula and Kammerling, 1988;Nassau, 1990).…”

Section: Introductionmentioning

confidence: 99%

Gemmological investigation of a synthetic blue beryl: a multi-methodological study

Adamo¹,

Gatta²,

Rotiroti³

et al. 2008

Mineral. mag.

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A multi-methodological investigation of a synthetic Cu/Fe-bearing blue beryl [IV(Be2.86Cu0.14)∑=3.00VI(Al1.83Fe3+0.14Mn2+0.03Mg0.03)∑=2.03IV(Si5.97Al0.03∑=6.00O18.(Li0.12Na0.04.0.40H2O)] has been performed by means of gemmological standard testing, electron microprobe chemical analyses, laser ablation inductively coupled plasma mass spectroscopy, thermo-gravimetric analyses, infrared spectroscopy and single-crystal X-ray diffraction in order to determine the gemmological properties, crystal structure and crystal-chemistry of this material. The increasing production of marketable hydrothermal synthetic beryls with 'exotic' colours and the small number of studies on the accurate location of chromophores in the crystal structure inspired this multi-methodological investigation. The X-ray structural refinements confirm that the space group of the Cu/Fe-bearing blue beryl is P6/mcc, with unit-cell parameters: 9.2483 ≤ a ≤ 9.2502 Å and 9.2184 ≤ c ≤ 9.2211 Å. The analysis of the difference Fourier maps of the electron density suggests that Cu is located at the tetrahedral site (Wyckoff 6fposition) along with Be, whereas Fe shares the octahedral site with Al (4c position). No evidence of extra-framework Cu/Fe-sites (i.e. channel sites) has been found. The Li is probably located at the extra-framework 2b site. Infrared spectra show that the H2O molecules are present with two configurations: one with the H···H vector oriented ‖[0001] and the other with H···H vector oriented ⊥[0001].

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Section: Introductionmentioning

confidence: 99%

Gemmological investigation of a synthetic blue beryl: a multi-methodological study

Adamo¹,

Gatta²,

Rotiroti³

et al. 2008

Mineral. mag.

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“…Synthetic blue beryl has been produced by hydrothermal growth techniques since the late 1980s Kammerling, 1988, 1991;Nassau, 1990Nassau, , 1997. Tairus, a Thai/Russian joint venture, produces synthetic blue beryl in Russia and markets it out of Bangkok (Smirnov et al, 1999).…”

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confidence: 99%

Aquamarine, Maxixe-Type Beryl, and Hydrothermal Synthetic Blue Beryl: Analysis and Identification

Adamo¹,

Pavese²,

Prosperi³

et al. 2008

Gems & Gemology

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This article presents a full characterization of a suite of aquamarines and other blue beryls of different origins by classic gemological and contemporary analytical techniques, in order to determine those features that may be diagnostic for their identification. MATERIALS AND METHODSWe examined a total of 25 natural, treated, and synthetic blue beryl specimens (see, e.g., figure 1): four faceted Brazilian aquamarines (0.18 to 1.54 ct); one faceted and one rough aquamarine from Nigeria (1.81 and 54.02 ct, respectively); three faceted (0.08-0.13 ct) and two rough (7.30 and 8.20 ct) aquamarines (marketed as "True Blue" beryl) from the Yukon Territory, Canada; one faceted Maxixe-type (irradiated) blue beryl (1.77 ct); three faceted Tairus hydrothermal synthetic blue beryls (2.03-3.50 ct);Aquamarine, Maxixe-type (irradiated) beryl, and two types of hydrothermally grown synthetic blue beryl currently available in the marketplace were investigated by classical gemological methods, chemical analysis, and UV-Vis-NIR and mid-IR spectroscopy. These materials may be conclusively identified by a combination of these techniques. The Maxixe-type beryl (like naturalcolor Maxixe beryls) is distinguishable by its unusual dichroism, green UV fluorescence (when present), Fe-free chemical composition, and distinctive UV-Vis-NIR spectrum. The hydrothermal synthetic blue beryls can be discriminated from their natural counterparts on the basis of microscopic features, chemical composition, and visible and infrared spectroscopic features.

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“…Kashan synthetic rubies were produced by Ardon Associates in Austin, Texas, U.S.A., from the end of the 1960s to the mid-1980s with a short renaissance in the mid-1990s (Nassau, 1990;Laughter, 1994;. The synthetic rubies are flux-grown from a cryolite-bearing melt (Gübelin, 1983;Henn and Schrader, 1985;Schmetzer 1986 a,b).…”

Section: Introductionmentioning

confidence: 99%

Formation of large synthetic zincite (ZnO) crystals during production of zinc white

Nowak¹,

Braithwaite²,

Nowak³

et al. 2007

Journ of Gemm

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Remarkable zincite crystals have formed as a by-product of zinc white production in Olawa Foundry, Poland. Some are of gem quality and have been faceted. Small primary crystals formed by reaction of zinc vapour with carbon dioxide from fuel burning gases leaking through faults in a diaphragm of a retort furnace. Some of these have undergone carbon monoxide-promoted and zinc vapour-assisted sublimation to form large secondary crystals. Many of these crystals are brightly coloured and transparent, and have been found up to 2 kg in weight. Most of the crystals are fluorescent in ultraviolet light.

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Synthetic Gem Materials in the 1980s

Cited by 13 publications

References 41 publications

Gemmological investigation of a synthetic blue beryl: a multi-methodological study

Gemmological investigation of a synthetic blue beryl: a multi-methodological study

Aquamarine, Maxixe-Type Beryl, and Hydrothermal Synthetic Blue Beryl: Analysis and Identification

Formation of large synthetic zincite (ZnO) crystals during production of zinc white

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