Reference the Sterling Mine GANJ_Calender_08.
The fluorescence of the Franklin ores was discovered accidentally in the early 1900s, when sparks from primitive electrical
equipment in the mines caused the rocks to glow. Sparking machines were quickly built, and fluorescence was soon being
used to follow ore zones and monitor the quality of mills production. Later, fluorescence was used to judge whether or not exploratory
drill holes passed close to the ore body. If the hole was close to the ore, calcite in rock cores retrieved from the holes would glow
red. Calcite further from the ore had no fluorescence.
This is willemite green and Calcite red