Hyalophane from the Famous Franklin Mine, Franklin, New Jersey
Contributed by: Chris Clemens
minID: K8C-M0V
Date: May 2nd, 2026
Locality: Mill site dump, Franklin Mine, Franklin, Sussex County, New Jersey, USA (See on Mindat)
Size: 46 x 32 x 54 mm
Weight: 88 g
Description:
Hyalophane is a barium rich variety of the feldspar mineral microcline that shows pink/magenta fluorescence under shortwave UV. In this specimen, the hyalophane occurs with non-fluorescent andradite garnet (red/brown) and black franklinite. This rock was collected by the author during the 2017 Super Dig at Franklin, New Jersey, and was found on the pile of material from the original Franklin Mill Site Dump.
Originally posted by Chris Clemens on Nature's Rainbows in 2018.
Summary of luminescence responses:
Microcline var. Hyalophane (Mindat) (RRUFF)
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Red