Trace Element Concentrations and Mineralogy of Quartz Vein Deposits from Southeastern Hubei Province, China

Abstract

Hydrothermal quartz samples collected from the Fujiashan and Yipanqiu quartz deposits in southeastern Hubei Province, China have been investigated by analytical combination of optical microscopy, scanning electron microscopy, and inductively coupled plasma optical emission spectroscopy, in conjunction with conventional beneficiation processing to evaluate their potential as sources of high purity quartz (HPQ) from a commercial perspective. Microscopy efforts reveal that major mineral impurities associated with quartz are K-feldspar, muscovite, iron oxides, rutile with accessory kaolinite. Bulk trace element concentrations of the processed quartz products demonstrate that the Fujiashan-II quartz vein with cumulative impurities of less than 50 μg g−1 with <30 μg g−1 Al and <10 μg g−1 Ti fits with the lattice-bound criteria for HPQ, meeting the requirement by a HPQ deposit. However, the Yipanqiu quartz deposits are not promising for HPQ production due to high fluid inclusion contents, intimate intergrowth texture with highly variable crystal size, and probably high lattice-bound element contents. The early Neoproterozoic Fujiashan quartz deposits have likely been experienced long-term retrograde metamorphism-related recrystallisation which might contribute to high-purity quartz formation. Due to a much younger crystallization age compared to the Fujiashan deposits, quartz grains in the middle Cretaceous Yipanqiu quartz vein retain high trace elements, leading to exclusion of being a HPQ deposit.