Trancas Geodes from Chihuahua MexicoFirst found in 1973, Trancas Geodes are most commonly found via surface mining in Chihuahua, Mexico. These amazing rocks are incredibly varied and you never know what ancient treasures you will uncover when you crack one open. Trancas may not be the most colorful geodes at first glance, but they flouresce wonderfully under short wave UV light due to trace uranium content, similar to Dugway Geodes from Utah. These wonderful rocks often feature stunning druzy crystalline centers.

Trancas Geodes range in size from under an inch to three inches and feature a thin skin.

Trancas Mines

Finding a location to hunt for your own Trancas Geodes has proven to be challenging. There are many private mines listed on but as of right now none that advertise the mining of Trancas geodes. We will continue hunting for mines allowing the digging of Trancas Geodes, but in the meantime there are many places online that offer Trancas Geodes for sale.

Trancas Thundereggs

While most Trancas Geodes feature a thing skin and amazing druzy centers, a small percentage present as thundereggs, meaning they contain solid or nearly solid agate centers. Finding a Trancas Thunderegg is a rare experience as many miners have ignored these stones over the years, favoring those with a higher chance of a hollow center.

How to Break a Trancas Geode

Whether you’ve discovered a Trancas Geode in the wild or purchased one from a rock show, cracking a geode can be done in many ways.


A hammer and chisel are the most cost effective way to crack a geode if you are not cracking geodes frequently. They are also a good option for trancas geodes as they are quite small and thin walled and may not require to force of a soil pipe cutter.

First and foremost, safety is the most important part of cracking a geode. Always make sure you wear well-fitting safety goggles and gloves to prevent injury.

Once you are geared up, place your Trancas geode on a flat wooden board, one that you won’t mind damaging, and definitely not your nice cutting board!

Use a flat bladed chisel to top a line around your geode. Once you have established a clean line that you can see, continue tapping your chisel around the geode. After several passes along this line, your Trancas geode should crack cleanly along it’s circumferance.

It’s very important to understand that this can be a time consuming process and don’t give into the tempation to just give it a few healthy wacks with your hammer. Geodes can be suprisingly fragile and shatter into many pieces.

Cracking a Trancas Geode at the Osage Beach Rock and Gem ShowSOIL PIPE CUTTER

Using a soil pipe cutter is one of the easiest ways to get a consistent, clean geode crack every time. While these tools may be hard to find and definitely on the pricey side, they are the go to tool for people that crack a lot of geodes on a regular basis.

When using a soil pipe cutter to crack a trancas geodes, the most important thing is safety! Make sure you always wear a pair of well-fitting safety googles and wear gloves to avoid injury from any shards. It’s also always helpful to have a partner to hold your geode to make sure it stays centered.

A soil pipe cutter is a tool featuring a bladed chain to cut through pipe easily, this makes it the perfect tool for cracking a rock in one motion without worry of shattering.

Before you insert your Trancas geode into the pipe cutter, open the handles wide. Then, carefully wrap the chain around your geode and pull it taught, hooking the closest chain pin into the socket on the cutting arm.

It’s helpful here to have a second set of hands, but if your chain is tight enough you should be able to pull the soil pipe cutter arms closed and crack your geode!





Author: Celeste