Thermal properties of gem-quality moganite-rich blue chalcedony
| dc.contributor.author | Hatipoǧlu M. | |
| dc.contributor.author | Tuncer Y. | |
| dc.contributor.author | Kibar R. | |
| dc.contributor.author | Çetin A. | |
| dc.contributor.author | Karal T. | |
| dc.contributor.author | Can N. | |
| dc.date.accessioned | 2025-04-10T11:15:28Z | |
| dc.date.available | 2025-04-10T11:15:28Z | |
| dc.date.issued | 2010 | |
| dc.description.abstract | In this study, thermal properties and thermal decompositions of dehydration behaviour of gem-quality translucent blue chalcedonies, without banding or crystalline centre structure, from the Sarcakaya-Eskiehir region in Turkey were studied by means of X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometry (ICP-AES), Fourier transform infrared (FT-IR), thermoluminescence (TL), and simultaneously two thermal analyses of (DTA/TGA) spectroscopy. X-ray diffraction patterns of the blue chalcedony indicate the presence of two important chalcedonic silica phases with overlapped peaks at 4.26, 3.34, 2.28, 2.13, 1.82, 1.54, 1.38, and 137 . During heating from the room temperature to 300 °C, the thermoluminescence pattern of the blue chalcedony shows a characteristic peak at 210 °C. This peak may be due to unusually high traces of the impurities S, Th, Tl, U, and W. During heating from the room temperature to 1400 °C, the TGA pattern of the blue chalcedony indicates that the weight loss is due to the silanol water loss only, and that this loss occurs in a wide temperature range between about 170 and 954 °C. In addition, after making some corrections concerning the artefact mass gain, being due to the drift with buoyancy effect of the atmosphere in its TGA curve, the moganite-rich blue chalcedony shows a relatively lower mass loss of 0.202%. The DTA pattern of the blue chalcedony displays both endothermic and exothermic behaviours because of silica phase transformations. There are one distinctive sharp endotherm and three weaker endotherms at 806 °C. In addition, there is one distinctive sharp exotherm and one weaker exotherm at 1270 °C. © 2010 Elsevier B.V. All rights reserved. | |
| dc.identifier.DOI-ID | 10.1016/j.physb.2010.08.048 | |
| dc.identifier.uri | http://hdl.handle.net/20.500.14701/51034 | |
| dc.title | Thermal properties of gem-quality moganite-rich blue chalcedony | |
| dc.type | Article |