Morphology of Barite Synthesized by In-Situ Mixing of Na<sub>2</sub>SO<sub>4</sub> and BaCl<sub>2</sub> Solutions at 200 °C
Chunyao Wang,
Li Zhou,
Shuai Zhang,
Li Wang,
Chunwan Wei,
Wenlei Song,
Liping Xu,
Wenge Zhou
Affiliations
Chunyao Wang
Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
Li Zhou
School of Geography and Environmental Science, Guizhou Normal University, Guiyang 550025, China
Shuai Zhang
Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
Li Wang
Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
Chunwan Wei
Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871, China
Wenlei Song
State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi’an 710069, China
Liping Xu
School of Fundamental Science, Zhejiang Pharmaceutical College, No. 666 Siming Road, Ningbo 315500, China
Wenge Zhou
Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
Barite is an abundant sulfate mineral in nature. Especially, the variety of morphologies of barite is often driven by the mixing of Ba-bearing hydrothermal fluid and sulfate-bearing seawater around hydrothermal chimneys. In order to better understand the factors affecting the morphology and precipitation mechanism(s) of barite in seafloor hydrothermal systems, we synthesized barite by a new method of in-situ mixing of BaCl2 and Na2SO4 solutions at 200 °C while varying Ba concentrations and ratios of Ba2+/SO42−, and at room temperature for comparison. The results show that barite synthesized by in-situ mixing of BaCl2 and Na2SO4 solutions at 200 °C forms a variety of morphologies, including rod-shaped, granular, plate-shaped, dendritic, X-shaped, and T-shaped morphologies, while room temperature barites display relatively simple, granular, or leaf-like morphologies. Thus, temperature affects barite morphology. Moreover, dendritic barite crystals only occurred at conditions where Ba2+ is in excess of SO42− at the experimental concentrations. The dendritic morphology of barite may be an important typomorphic feature of barite formed in high-temperature fluids directly mixing with excess Ba2+ relative to SO42−.
