Barite Crystals - Linwood Mine, Buffalo, Iowa

Contributed by: Chris Clemens
minID: VKK-58G
Date: May 20th, 2026
Locality: Linwood Mine, Buffalo, Scott County, Iowa, USA (See on Mindat)
Size: 10.7 x 9.4 x 11.9 cm
Weight: 833 g

Description:
This is a large cluster of intergrown, prismatic, light golden/smoky colored barite crystals, on a minimal limestone matrix. It was collected in 2016 from the Linwood Mine, Scott County, Buffalo, Iowa. It shows a similar blue/white, fluorescent response under all wavelengths of UV, brightest under shortwave and midwave. It is also phosphorescent, again most brightly following shortwave and midwave UV.

Located adjacent to the Mississippi River, the Linwood Mine is one of the largest underground limestone mines currently in operation in the United States.

Originally posted by Chris Clemens on Nature's Rainbows in 2016.

Fluorescence under shortwave UV light.

Afterglow after exposure to shortwave UV light.

Fluorescence under midwave UV light.

Afterglow after exposure to midwave UV light.

Fluorescence under longwave UV light.

Afterglow after exposure to longwave UV light.

Normal light.

Summary of luminescence responses:

Baryte (Mindat) (RRUFF)

• Fluorescence under Longwave (365nm Lamp/Mercury) UV light: Blue
• Afterglow after exposure to Longwave (365nm Lamp/Mercury) UV light: Green
• Fluorescence under Midwave (305nm Lamp/Mercury) UV light: Blue
• Afterglow after exposure to Midwave (305nm Lamp/Mercury) UV light: Blue
• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Blue
• Afterglow after exposure to Shortwave (254nm Lamp/Mercury) UV light: Blue