Red Phantoms in Mariposa (Butterfly) Calcite from Santa Eulalia, Mexico

Contributed by: FMS Admin
Date: Mar 1st, 2026
Locality: Santa Eulalia Mining District, Aquiles Serdán Municipality, Chihuahua, Mexico (See on Mindat)
Size: 3.5 x 3 x 7.5 cm

Description:
This specimen could be classified as a "common Mariposa Calcite" from the Buena Tierra Mine, Santa Eulalia, Mexico.

It has some nice characteristics. It has one surface covered by tan crystals up to several centimeters wide. These crystals do not fluoresce at all but show interesting phantoms.

The opposite side is not so nice in natural light but in SW fluoresce red-orange showing beautiful phantoms.
Let me say that some of them are awesome.

Another side of the specimen is also amazing in MW. The fluorescence is less intense than in SW, but you can see yellow, lilac, red and green hues.

A negligible phosphorescence is also present.

Originally posted by Stefano Buzzoni on Nature's Rainbows.