Trancas Geodes

“Trancas geodes with crystals are quite different from their famous cousins, the Las Choyas geodes. Trancas geodes, also known as "Chihuahua geodes" were discovered in 1971 in Chihuahua, Mexico.

Trancas geodes are generally small - just two to four inches in size. They are not very colorful with only pale colors typically ranging from white to gray or blue, but they make up for a lack of color because they often produce fabulous drusy quartz centers. The centers usually contain clear quartz, chalcedony, calcite, aragonite and sometimes quartz scepters.

Trancas geodes may also contain a form of quartz that is rather hard to categorize. It might be best described as “curved finger-like projections.” Some have described Trancas geodes as miniature caves with stalactites and stalagmites lining the hollow interior. Trancas geodes have a thin outer shell that is usually gray, brown, cream or peach colored.

A fun bonus with Trancas geodes is that they tend to fluoresce green under short-wave UV light because many contain a small amount (not harmful) of uranium. While most contain hollow centers, some Trancas geodes present as thundereggs with a completely solid or nearly solid agate center. This is not considered as desirable as the drusy quartz centers.”

Credits; Rock & Gem Magazine staff article dated September 10, 2023