History · Geology
About Dachang Tin-Polymetallic Field
The Dachang tin-polymetallic field in Nandan County, northwest Guangxi, is one of the world’s largest tin deposits and a key collector locality for Sn-Pb-Zn-Sb sulfosalt species. The deposit is hosted in Devonian carbonates intruded by Mesozoic granite, producing a complex skarn and vein-replacement ore system.
Mining context
The mine field includes Tongkeng, Lamo, Changpo, Longtoushan and other sub-deposits. Modern Cassiterite-sulfide ores grade 1-2% Sn with significant Pb-Zn-Sb co-products. The field has been mined intermittently since the Han Dynasty.
Notable Minerals
Cassiterite, sphalerite (chocolate-brown ferroan variety), jamesonite needles, pyrrhotite, arsenopyrite, dachangite (its type locality), and emerald-green beryl from associated pegmatites. Some of the world’s most spectacular emerald-color beryl matrix specimens come from Dachang.
Collector Notes
Dachang produces unique chocolate-brown sphalerite cubes and superb cassiterite twins. Its emerald-green beryl in fluorite-quartz matrix is one of the most distinctive Chinese pegmatite specimens.
Minerals Produced Here
- Agate (玛瑙)
- Amethyst (紫水晶)
- Arsenopyrite (毒砂矿)
- Beryl (绿柱石)
- Cassiterite (锡石)
- Chalcedony (玉髓)
- Citrine (黄水晶)
- Fluorite (萤石)
- Jamesonite (脆硫锑铅矿)
- Jasper (碧玉)
- Muscovite (白云母)
- Pyrrhotite (磁黄铁矿)
- Quartz (石英 / 水晶)
- Rose Quartz (玫瑰石英)
- Sphalerite (闪锌矿)
