Calcite, San Antonio Mine, Santa Eulalia, Chihuahua, Mexico
Contributed by: Chris Clemens
minID: AG5-27E
Date: Apr 18th, 2026
Locality: San Antonio Mine, East Camp, Santa Eulalia Mining District, Aquiles Serdán Municipality, Chihuahua, Mexico (See on Mindat)
Size: 6 x 2.5 x 9.5 inches
Weight: 2.5 lb
Description:
The San Antonio Mine is located near Chihuahua, Mexico, and is an underground operation that produces sphalerite, galena and cassiterite. The host rock is limestone from the Upper Cretaceous period, dated 100 to 66 million years old.
Bright, saturated, orange fluorescence is seen under shortwave UV (254 nm). This calcite shows similar, but much dimmer fluorescence under midwave and longwave UV.
Originally posted by Chris Clemens on Nature's Rainbows in 2020.
Summary of luminescence responses:
Calcite (Mindat) (RRUFF)
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Red