An assessment of alloying elements and hardness in gold and silver jewelleries
Wuritka E. G.*, Tajudeen B. and Dung Z. E.
Research Article | Published September 2014
Advancement in Scientific and Engineering Research, Vol. 2(3), pp. 41-47
Department of Industrial Design, Abubakar Tafawa Balewa University, P.M.B. 0248 Bauchi State, Nigeria.
*Corresponding author: E-mail:
wuritkagotringenock@gmail.com
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To exploit the technology of the quality of gold and silver jewelleries, they were subjected to analysis for their alloying composition and their hardness. The compositions were determined by suing X-RF spectrometric method and Rockwell Hardness; Tester on B-scale. The elemental constituents showed that gold jewellery contains Ca (0.73%), Cr (0.13%), Fe (0.33%), Ni (0.09%), Cu (1.90%), Pd (1.70%) and Au (84.90%) while silver jewellery contains Si (1.00%), Ca (0.001), Cr (0.069%), Fe (0.21%), Ni (0.25%), Cu (4.19%, Zn (1.36%), Y (0.5%) and Ag (92.80%) as their oxides. The result of the compositional analysis showed that the jewelleries have heavy elements and when these elements are used as alloying metals in jewelleries they seem to have adverse effects on the users. Other elements might be additions as grain refiners, de oxidizers impurities that help in improving the mechanical properties of the jewelleries. The hardness result showed gold (65 HBR) to be harder than silver
(61.7 HBR). Pearson correlation of the metals at 95% confidence with hardness showed that all the jewellery types studied indicated lack of correlation. However, this could not be clearly supported by the plots of the various metal concentrations in the jewelleries against their hardness as the plots of hardness against percent metals suggested both positive and negative correlation. Some metal associated with the jewelleries are soft metals as such they could be prune to scratches and the pores created may habour bacteria. The presence of trace metals or heavy metals which are toxic in the jewelleries may also pose a serious health hazard and potential dangers associated with wearing of jewelleries by unsuspecting users.
Keywords: Alloying elements, jewelleries, hardness, toxic elements.
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Citation: Wuritka EG, Tajudeen B, Dung ZE (2014). An assessment of alloying elements and hardness in gold and silver jewelleries. Adv. Sci. Eng. Res. 2(3): 41-47
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