Bi-Ag-Sulfosalts and Sulfoarsenides in the Ruwai Zn-Pb-Ag Skarn Deposit, Central Borneo, Indonesia
The Ruwai skarn deposit is located in the Schwaner Mountain complex within the central Borneo gold belt and is currently considered the largest Zn skarn deposit in Indonesia. The deposit has been known to host Zn-Pb-Ag mineralization in the form of massive sulfide ore bodies; however, the occurrence...
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MDPI AG
2022-12-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/12/12/1564 |
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| author | Cendi D. P. Dana Andrea Agangi Arifudin Idrus Chun-Kit Lai Doly R. Simbolon |
| author_facet | Cendi D. P. Dana Andrea Agangi Arifudin Idrus Chun-Kit Lai Doly R. Simbolon |
| author_sort | Cendi D. P. Dana |
| collection | DOAJ |
| description | The Ruwai skarn deposit is located in the Schwaner Mountain complex within the central Borneo gold belt and is currently considered the largest Zn skarn deposit in Indonesia. The deposit has been known to host Zn-Pb-Ag mineralization in the form of massive sulfide ore bodies; however, the occurrence of Ag-bearing minerals has not been identified yet. This study documents the mineralogical characteristics of several Bi-Ag sulfosalts and sulfoarsenides, as well as their chemical compositions. Ten Bi-Ag sulfosalts were identified, including native bismuth, tetrahedrite, cossalite, tsumoite, bismuthinite, joseite-B, Bi<sub>6</sub>Te<sub>2</sub>S, Bi-Pb-Te-S, Bi-Ag-S, and Bi-Te-Ag. Three sulfoarsenides were identified, including arsenopyrite, glaucodot, and alloclasite. The occurrence of Bi-Ag sulfosalts is typically associated with massive sulfide mineralization, although tsumoite can also be found associated with massive magnetite. In terms of sulfoarsenides, both arsenopyrite and glaucodot are associated with massive sulfide mineralization, whereas alloclasite is associated with massive magnetite mineralization. The Bi-bearing minerals are characterized by irregular, bleb-like texture or patch morphology, and occur either as free grains or inclusions within sulfides, such as galena or pyrite. Tetrahedrite typically has an anhedral shape with a rim or atoll texture surrounding sphalerite or galena. In contrast, sulfoarsenides are typically found as euhedral–subhedral grains where glaucodot typically is rimmed by arsenopyrite. Both Bi-Ag sulfosalt and sulfoarsenides were formed during the retrograde stage under high oxidation and a low sulfidation state condition. The ore-forming temperature based on arsenopyrite geothermometry ranges from 428 °C to 493 °C. |
| first_indexed | 2024-03-09T16:04:10Z |
| format | Article |
| id | doaj.art-58d78eef5eb343abb3cb76c6ee98352e |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-09T16:04:10Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-58d78eef5eb343abb3cb76c6ee98352e2023-11-24T16:51:55ZengMDPI AGMinerals2075-163X2022-12-011212156410.3390/min12121564Bi-Ag-Sulfosalts and Sulfoarsenides in the Ruwai Zn-Pb-Ag Skarn Deposit, Central Borneo, IndonesiaCendi D. P. Dana0Andrea Agangi1Arifudin Idrus2Chun-Kit Lai3Doly R. Simbolon4Earth and Planetary Science Institute, School of GeoSciences, The University of Edinburgh, Edinburgh EH9 3FE, UKGraduate School of International Resource Sciences, Akita University, Akita 010-0852, JapanDepartment of Geological Engineering, Universitas Gadjah Mada, Yogyakarta 55281, IndonesiaFortescue Metals Group Ltd., East Perth, WA 6004, AustraliaPT Kapuas Prima Coal, Tbk., North Jakarta 14460, IndonesiaThe Ruwai skarn deposit is located in the Schwaner Mountain complex within the central Borneo gold belt and is currently considered the largest Zn skarn deposit in Indonesia. The deposit has been known to host Zn-Pb-Ag mineralization in the form of massive sulfide ore bodies; however, the occurrence of Ag-bearing minerals has not been identified yet. This study documents the mineralogical characteristics of several Bi-Ag sulfosalts and sulfoarsenides, as well as their chemical compositions. Ten Bi-Ag sulfosalts were identified, including native bismuth, tetrahedrite, cossalite, tsumoite, bismuthinite, joseite-B, Bi<sub>6</sub>Te<sub>2</sub>S, Bi-Pb-Te-S, Bi-Ag-S, and Bi-Te-Ag. Three sulfoarsenides were identified, including arsenopyrite, glaucodot, and alloclasite. The occurrence of Bi-Ag sulfosalts is typically associated with massive sulfide mineralization, although tsumoite can also be found associated with massive magnetite. In terms of sulfoarsenides, both arsenopyrite and glaucodot are associated with massive sulfide mineralization, whereas alloclasite is associated with massive magnetite mineralization. The Bi-bearing minerals are characterized by irregular, bleb-like texture or patch morphology, and occur either as free grains or inclusions within sulfides, such as galena or pyrite. Tetrahedrite typically has an anhedral shape with a rim or atoll texture surrounding sphalerite or galena. In contrast, sulfoarsenides are typically found as euhedral–subhedral grains where glaucodot typically is rimmed by arsenopyrite. Both Bi-Ag sulfosalt and sulfoarsenides were formed during the retrograde stage under high oxidation and a low sulfidation state condition. The ore-forming temperature based on arsenopyrite geothermometry ranges from 428 °C to 493 °C.https://www.mdpi.com/2075-163X/12/12/1564Ruwaiskarnsulfosaltsbismuthsilverarsenides |
| spellingShingle | Cendi D. P. Dana Andrea Agangi Arifudin Idrus Chun-Kit Lai Doly R. Simbolon Bi-Ag-Sulfosalts and Sulfoarsenides in the Ruwai Zn-Pb-Ag Skarn Deposit, Central Borneo, Indonesia Minerals Ruwai skarn sulfosalts bismuth silver arsenides |
| title | Bi-Ag-Sulfosalts and Sulfoarsenides in the Ruwai Zn-Pb-Ag Skarn Deposit, Central Borneo, Indonesia |
| title_full | Bi-Ag-Sulfosalts and Sulfoarsenides in the Ruwai Zn-Pb-Ag Skarn Deposit, Central Borneo, Indonesia |
| title_fullStr | Bi-Ag-Sulfosalts and Sulfoarsenides in the Ruwai Zn-Pb-Ag Skarn Deposit, Central Borneo, Indonesia |
| title_full_unstemmed | Bi-Ag-Sulfosalts and Sulfoarsenides in the Ruwai Zn-Pb-Ag Skarn Deposit, Central Borneo, Indonesia |
| title_short | Bi-Ag-Sulfosalts and Sulfoarsenides in the Ruwai Zn-Pb-Ag Skarn Deposit, Central Borneo, Indonesia |
| title_sort | bi ag sulfosalts and sulfoarsenides in the ruwai zn pb ag skarn deposit central borneo indonesia |
| topic | Ruwai skarn sulfosalts bismuth silver arsenides |
| url | https://www.mdpi.com/2075-163X/12/12/1564 |
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