Fluorescent Calcite Diamond - Palmarejo Mine, Chínipas, Chihuahua, Mexico

Contributed by: Chris Clemens
minID: M6A-JA0
Date: May 21st, 2026
Locality: Palmarejo Mine, Palmarejo, Chínipas Municipality, Chihuahua, Mexico (See on Mindat)
Size: 9.2 x 6.3 x 11.9 cm
Weight: 803 g

Description:
This unique fluorescent specimen comes from the Palmarejo Mine, in Chínipas, Chihuahua, Mexico, and consists of a brightly fluorescent calcite scalenohedron encased in a non-fluorescent calcite fishtail twin crystal. Under shortwave and midwave UV the internal calcite scalenohedron fluoresces bright red/orange. The fluorescent scalenohedron can be clearly seen in cross section where the specimen is cleaved at the base, producing a distinct fluorescent diamond shape surrounded by non-fluorescent calcite. This complex specimen was formed by multiple generations of growth of calcite and manganese oxide minerals, with the end result producing a brightly fluorescent central calcite scalenohedron, encased in layers of essentially non-fluorescent calcite and outlined in black manganese oxide.

Originally posted by Chris Clemens on Nature's Rainbows in 2020.

Fluorescence under shortwave UV light.

Normal light.

Fluorescence under shortwave UV light. Side 2

Normal light. Side 2.

Summary of luminescence responses:

Calcite (Mindat) (RRUFF)

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