Inclusion and Trace Element Characteristics of Emeralds from Swat Valley, Pakistan

Abstract

Pakistan's production of emeralds has been increasing in recent years, and reserves are estimated at almost 70 million carats (Jamal-ud-Din, 2014;Makki and Ali, 2019). Swat Valley is known for small stones with saturated color (figure 1). Mineralogical curiosities include three-phase fluid inclusions (Gübelin, 1982) and newly discovered trapiche-type emeralds (Khan, 2018). Photomicrographs of three-phase inclusions in Swat emeralds are provided for the first time in this study.The history and geology of the Swat deposit were comprehensively reported by Arif et al. (2011) and Giuliani et al. (2019) and are summarized here. However, a detailed study of the inclusions and trace elements of Swat emeralds has not been published despite analytical and geological advances (Bowersox and Anwar, 1989;Gao et al., 2019).Therefore, we present results from a detailed study of gemological properties, inclusions, spectroscopy, and chemical composition to characterize the emeralds from Swat Valley. Our findings provide insights that can be used for understanding the genesis of the emeralds in this deposit while shedding light on the geographic origin determination of emerald.

Water Molecules in Channels of Natural Emeralds from Dayakou (China) and Colombia: Spectroscopic, Chemical and Crystal Structural Investigations

“…As shown in Figure 7, there is a significant positive correlation between the alkali content and the peak intensity. In previous studies, the 5273 cm −1 band was commonly ascribed to type I H2O according to the orientation of measurement [14,23,29], but occasionally related to type II H2O [24,34]. Since the obvious positive correlation observed in Figure 7, this band is assigned to H2O II ν2+ν3 here.…”

“…Furthermore, the difference in bond lengths between Na + and oxygen atoms of water molecules results in the different IR absorption bands of type IIs and IId H 2 O. Extensive research has recorded the IR bands corresponding to the three vibration modes of type I, IIs and IId H 2 O [1,2,4,7,9,11,14,[16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. However, there are currently no consensuses on the ν 1 band of type I H 2 O and the ν 3 band of type IIs H 2 O. Additionally, the IR bands of H 2 O related to Li + or Cs + have not been determined.…”