History · Geology
About Tengchong Volcanic Field
The Tengchong Volcanic Field in western Yunnan Province is one of China’s few historically active volcanic regions and the country’s premier source of native sulfur. Modern fumarolic activity at the Rehai geothermal area continues to deposit vivid yellow sulfur crystals around vents and hot springs. The field also produces realgar, orpiment, and rare arsenic-bearing minerals tied to the active hydrothermal system.
Geology & Signature Specimens
Tengchong sits over a Cenozoic continental volcanic arc. Sulfur crystals form by direct sublimation from H₂S- and SO₂-rich vent gases. Specimens are typically smaller than Sicilian counterparts but exceptionally vivid lemon-yellow with dipyramidal habit.
