Phlogopite on Calcite - Afghanistan

Contributed by: Mark Cole
Date: Apr 11th, 2026
Locality: Sar-e-Sang, Kuran wa Munjan District, Badakhshan, Afghanistan (See on Mindat)
Size: 3.5 x 3 x 4.5 inches
Weight: 1.73 lb

Description:
Phlogopite is found in matrix on marble and calcite usually. The marble is not fluorescent, but the calcite pieces are very nice - offering a striking pink/red background for the bright yellow fluorescing phlogopite crystals. Many of the crystals on this piece are nicely gemmy. On this specimen the phlogopite is bright yellow under SW UV. The calcite fluoresces under both SW and MW but is brightest under MW. Displaying it under both lights offer the best color (first picture). The longwave picture is shown just for interest - a dull white fluorescence.

Originally posted by Mark Cole on Nature's Rainbows in 2017.

Fluorescence under midwave and shortwave UV light.

Fluorescence under shortwave UV light.

Fluorescence under midwave UV light.

Fluorescence under longwave UV light.

Normal light.

Summary of luminescence responses:

Phlogopite (Mindat) (RRUFF)

• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Yellow

• Fluorescence under Midwave (305nm Lamp/Mercury) UV light: Red
• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Red