History · Geology
About Llallagua (Siglo XX)
Llallagua (Siglo XX), in central Bolivia, is one of the world’s greatest tin districts and the source of legendary phosphate-mineral specimens — vivianite, ludlamite, paravauxite, wavellite — alongside spectacular cassiterite-wolframite-pyrite combinations.
Geology
The deposit is an epithermal tin-silver vein system in shales and quartzites of the Llallagua Formation, intruded by quartz-feldspar porphyries. Multiple stages of mineralization produced complex Sn-W-Bi-As ore + late-stage phosphate-rich pockets.
Notable Minerals
Cassiterite (lustrous black twins), wolframite/ferberite (large bladed crystals), pyrite (octahedral and pyritohedral), arsenopyrite, vivianite (deep blue-green prismatic crystals — world’s best), ludlamite (apple-green), paravauxite, wavellite, siderite.
Collector Notes
Llallagua vivianite is unrivaled — large, lustrous, gem-clear deep-blue crystals on cassiterite or wolframite matrix are top-tier specimens. Pair with Yaogangxian (Hunan) for the world’s W-Sn collector tour.
Minerals Produced Here
- Agate (玛瑙)
- Amethyst (紫水晶)
- Arsenopyrite (毒砂矿)
- Cassiterite (锡石)
- Chalcedony (玉髓)
- Citrine (黄水晶)
- Ferberite (钨铁矿)
- Jasper (碧玉)
- Ludlamite (磷铁锰石)
- Pyrite (黄铁矿)
- Quartz (石英 / 水晶)
- Rose Quartz (玫瑰石英)
- Siderite (菱铁矿)
- Vivianite (蓝铁矿)
- Wolframite (黑钨矿)
