Plumbogummite ps. after Pyromorphite - Yangshuo Mine, China
Contributed by: Chris Clemens
minID: PRG-8Q3
Date: May 24th, 2026
Locality: Yangshuo Mine, Yangshuo Co., Guilin, Guangxi, China (See on Mindat)
Size: 14.5 x 7.9 x 16.3 cm
Weight: 652 g
Description:
This is a large specimen consisting of pale sky-blue plumbogummite pseudomorph that has replaced an intergrown cluster of hexagonal pyromorphite prisms, from the Yangshuo Mine, Yangshuo County, Guilin Prefecture, Guangxi Ahuang Autonomous Region, China. Little to no matrix is present. Some residual yellow-green unaltered pyromorphite can still be seen at the ends of some of the crystals.
The plumbogummite fluoresces under all UV wavelengths but is best under midwave UV. Under midwave UV (302 nm), the plumbogummite shows a bright green response while bright orange accents are provided by residual unaltered pyromorphite. Under shortwave UV (254 nm), the plumbogummite fluoresces green and the unaltered pyromorphite shows a burnt orange response. The green fluorescence is likely activated by uranyl (UO2+2) as evidenced by the radioactivity emitted by this specimen (approx. 200 cpm / 10x background). Bright, monochromatic, pale blue fluorescence is seen under longwave UV (365 nm).
Note: Although these Chinese plumbogummite pseudomorphs are usually attributed to the Yangshuo Mine, a new report published by Wilson and Moore in the Nov-Dec, 2022 issue of The Mineralogical Record (The Laohuan Mine, pp 697-732) indicates that this locality information is incorrect and that the true location is the Laohuan Mine, which is located approximately 10 km to the north.
Comment by M. Cole: The exact source has always been in question. I asked a reliable authority located in China. He says "It is called Laohuyan, Laohu means Tiger and Yan means big Rock or Cliff, it's on the back of the mountain of Yangshuo Pb-Zn Mine, and it is not a "mine"."
Originally posted by Chris Clemens on Nature's Rainbows in 2022.
Summary of luminescence responses:
Plumbogummite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm Lamp/Mercury) UV light: Blue
- Fluorescence under Midwave (305nm Lamp/Mercury) UV light: Green
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Green
- Fluorescence under Midwave (305nm Lamp/Mercury) UV light: Yellow
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Yellow