2017 Annual Meeting of Japan Association of Mineralogical Sciences field trip report: Excursion to the Ichinokawa stibnite mine, Saijo City, Ehime Prefecture

Abstract

Excursion to the Ichinokawa stibnite mine, Saijo City, Ehime Prefecture was held in 2017 Annual Meeting of Japan Association of Mineralogical Sciences at September 15, 2017, organized by Japan Association of Mineralogical Sciences. The field trip was arranged to get an understanding about the mineralogy, geology, and mining history of the Ichinokawa Mine as represented by the largest stibnite crystal in the world. 21 participants of the field trip were guided by Dr. Tetsuo Minakawa (Ehime University), Dr. Toru Inoue (Hiroshima University), and the staff of Geodynamics Research Center, Ehime University. At the first stop, we visited the Ichinokawa Community Center and the old Ichinokawa Mine. The community center located near the old Ichinokawa Mine preserves the historical documents and ore specimens of the Ichinokawa Mine. Specimens of stibnite crystals and stibnite veins in conglomerate are displayed there. We also visited to the old Senga-ko adit of the Ichinokawa Mine and the exposure of the Ichinokawa conglomerate nearby. For the second stop, we observed stibnite vein in schists at the riverside of the Kamogawa river. For the third stop, the ore collection collected by Mr. Daisuke Tanaka were observed at the Saijo City Local History Museum. The collection contains large stibnite aggregate up to 45.5 cm in length and 13.13 kg in weight, composed of prismatic crystals with a significant metallic luster, collected and donated by Mr. Daisuke Tanaka. The field trip provided us valued opportunity to study the geology of Ichinokawa and significant stibnite specimens at the locality, and to think the importance of the specimens and fields.