1" Purple Cubic Fluorite Crystals on Arsenopyrite - Yaogangxian Mine

This is a beautiful fluorite crystal cluster with purple phantoms, that formed in association with arsenopyrite. It was collected from the Yaogangxian Mine in the Hunan Province of China. Under short-wave ultraviolet light, the fluorite exhibits a vibrant purple fluorescence.

This specimen has been mounted to an acrylic display base with mineral tack.

The Yaogangxian mine is a tungsten-tin deposit in the Nanling Mountains of Hunan, China. The mine field is about 4 x 2.5 km (2.5 x 1.5 miles) and includes two primary deposits; the Yaogangxian quartz vein-type, tungsten-tin deposit and the Heshangtan skarn-type, tungsten-tin deposit.

The Yaogangxian quartz vein-type, tungsten-tin deposit (with minor greisen-style mineralization) has been mine since 1914 and hosts minor copper, tungsten, silver, lead, zinc and bismuth minerals. The Heshangtan skarn-type, tungsten-tin deposit has been mined since the 1960's and hosts a variety of associated silver ores. Both of these deposits are a result of the Mesozoic Yaogangxian pluton (composed of biotite-granite, porphyritic granite and quartz porphyry) which intruded into Cambrian-Devonian sediments and Jurassic limestones.

A variety of high quality mineral specimens are collected from this site. Some of the most popular minerals include arsenopyrite, bismuthinite, manganese-bearing calcite (manganocalcite), chalcopyrite, ferberite, fluorite, hübnerite, molybdenite, pyrite, rhodochrosite, siderite, stibnite, topaz and tungstite.

Arsenopyrite is an iron arsenic sulfide with the chemical formula FeAsS. Depending on minerals present during formation, the iron can be replaced by cobalt (Cobaltite). Arsenopyrite is the most common mineral containing arsenic and can be found in igneous, metamorphic and sedimentary rock. Crystals can be found as prismatic, twinned, columnar, elongated and massive formations within veins and are found in locations all around the world.

Arsenopyrite contains a significant amount of poisonous arsenic, making it somewhat toxic. Therefore, washing hands following handling of arsenopyrite specimens, is recommended.

Fluorite & Arsenopyrite
Yaogangxian Mine, Yaogangxian W-Sn ore field, Yizhang Co., Hunan, China
Entire specimen: 1" wide