The Effects of Heat Treatment on Zircon Inclusions in Madagascar Sapphires

Applications of Laser Ablation—Inductively Coupled Plasma—Mass Spectrometry (LA-ICP-MS) to Gemology

“…With the increased use of LA-ICP-MS in gem laboratories and the importance of detecting low ppm levels of Be in corundum, the need for standardization between gemological labs has grown. lower than the LA-ICP-MS detection limit of about 0.1 ppm (or 0.2 ppma), and internal features indicate that the corundum has been heated (see, e.g., Emmett et al, 2003;Wang et al, 2006), the stone should be identified as having undergone traditional heat treatment (i.e., without beryllium diffusion). The laboratory report may state "indications of heating" only.…”

Red gemstone characterization by micro‐Raman spectroscopy: the case of rubies and their imitations

“…In this case, the presence of glass infiltrations and zircon inclusions, the latter associated with baddeleyite, strongly suggests the hypothesis of glass filling and heating treatments for the sample R9 . In fact, recent studies on treated Madagascar corundum report the occurrence of subsolidus reactions of zircon inclusions with the subsequent formation of baddeleyite and the preservation of the euhedral morphology of the zircons. Therefore, sample R9 can be classified as natural ruby subjected to heat treatment and glass filling, aimed to reduce the surface perceptibility of fractures and cavities extended along the rim of the gem.…”

Spectroscopic study of inclusions in gem corundum from Mercaderes, Cauca, Colombia

“…The difference of this hypothetical and the actually observed band position may then be used for stress estimations. Note that our approach is different from that of Wang et al (2006) , obtained from two free-standing zircon crystals, as "zero-pressure Raman shift", even though their zircon inclusions showed notable band broadening. Neglecting the band downshift induced by radiation damage results in calculation of too low band upshift and hence underestimated compressive stress in the study of Wang et al (2006).…”

“…The Raman technique analysis has become, as a matter of course, particularly important in cases when facetted and/or mounted corundum (Al 2 O 3 ) and other gemstones are to be studied in a strictly non-destructive manner (Fritsch et al 2012; see also Kiefert et al 2001;Pinet et al 1992;Bersani and Lottici 2010). In analysing zircon (ZrSiO 4 ) inclusions inside such gem-corundum specimens, Raman and also photoluminescence (PL) spectroscopy are excellent methods to gain additional information such as (1) estimates of the degree of radiation damage in zircon crystals confined within a host corundum, (2) determination of pressures acting on such inclusions, and (3) hints to the provenance assignment of gems of unknown origin (Wanthanachaisaeng et al 2006;Wang et al 2006;Wanthanachaisaeng 2007;Noguchi et al 2013).…”