Rb, Sr, Nd and Sm concentrations in quartz

George R. Rossman, D. Weis, and G.J. Wasserburg
Division of Geological and Planetary Sciences
California Institute of Technology, Pasadena, CA  91125, USA

Abstract

    The concentrations of Rb, Sr, Nd and Sm in quartz crystals from Crystal Peak, Colorado; Steewart Mine, California; Tomas Gonzaga, Minas Gerais, Brazil; and Coleman Mines, Arkansas, were determined by isotope dilution mass spectrometry. Concentrations ranged from : 1.1y to 177 ppb Rb; 3.26 to 1027 ppb Sr; 0.0159 to 0,.48 ppb Sm; 0.127 to 2.81 ppb Nd. In the Brasilian crystal, concentrations of these elements were correlated with the amount of fluid inclusion water measured visually by turbidity and quantitatively with infrared absorption spectroscopy. The highest Rb content was found for a crystal free of visible inclusions, indicating that small amounts of Rb can also occur in quartz itself. Rb and Sr contents are much lower in synthetic quartz grown commercially from the Arkansas quartz.