Youngite - Youngite Cave, Guernsey, Platte Co., Wyoming
Contributed by: Mark Cole
Date: Mar 27th, 2026
Locality: Guernsey, Platte County, Wyoming, USA (See on Mindat)
Description:
Originally posted by Mark Cole on Nature's Rainbows in 2015.
Summary of luminescence responses:
Chalcedony (Mindat) (RRUFF)
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Green