Adamite - Ojuela Mine, Mapimí, Durango, Mexico
Contributed by: Chris Clemens
minID: 2HQ-D26
Date: May 1st, 2026
Locality: Ojuela Mine, Mapimí, Mapimí Municipality, Durango, Mexico (See on Mindat)
Size: 45 x 28 x 65 mm
Weight: 72 g
Description:
This is an interesting specimen of adamite from the Ojuela Mine, Mapimí, Durango, Mexico. As is the case with many fluorescent minerals, there tends to be tremendous variability in the brightness of the fluorescent response among various adamite specimens, even those from the same location. Some fluoresce only dimly under shortwave and show little to no response under longwave, while others fluoresce brightly under both wavelengths. This specimen is one of the brightest that I've seen and responds nicely under both UV wavelengths. In addition, the bright green, fluorescent adamite crystals sit on a bed of smaller white crystals of a second, unidentified mineral (perhaps calcite or aragonite) that fluoresce blue to blue/white and provide a beautiful color contrast to the brightly fluorescent adamite. The unidentified mineral is also phosphorescent.
The specimen has yellow colored adamite crystals perched on a bed of the unknown white mineral, all on top of a contrasting matrix of red/brown limonitic gossan. The well-developed adamite crystals fluoresce bright green, and the smaller unknown mineral crystals show a blue response under shortwave UV. The unknown mineral displays blue phosphorescence after the shortwave source is turned off. The specimen shows a similar, but less bright fluorescent response under longwave UV. The phosphorescence of the unknown mineral crystals is also dimmer following longwave but interestingly has undergone a color shift to pale green.
Originally posted by Chris Clemens on Nature's Rainbows in 2017.
Summary of luminescence responses:
Adamite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: Green
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Green