How To Break Open A Geode!
There are several ways to break open geodes. The most popular way (hammer/chisel method) is described below. First, we do want to stress that Keokuk area geodes especially should not be sawed open, as this process always destroys interior minerals such as calcites or selenite blades if the minerals are along the path of the saw blade and the shells do not look as nice as the agate skins to the Mexican geodes. Cracking the geode may avoid these crystals as well as giving the shell of the geode a more natural look. Mexican "coconut" geodes, however, can be sawed open but you still run the risk of damaging interior minerals. Many of these geodes, however, do look very attractive polished.
Below I will describe the most popular method to opening geodes (besides sawing them). There are many different ways to open a geode, but no matter how you do it, the key is PATIENCE, PATIENCE, PATIENCE! If you want the geode to break into two halves, you absolutely CANNOT just hit it as hard as you want to with a hammer! If it is hollow, you will be left with pieces in most cases, not two halves!
HAMMER/CHISEL METHOD: This is the most popular way to open a geode since most people have a hammer and chisel available around the house or in a toolbox versus some of the more specialized methods that mainly rock collectors have that are listed below. To open a geode with a hammer and chisel, score the geode all the way around the circumference of the geode with the chisel. We suggest using a flat-faced (regular) chisel end versus the pointed type, since the force from a pointed chisel will be directed over one spot versus over a larger area with the flat-faced chisel (better chances of opening along the line you want it to open on!). Continue this process until you see a crack develop in the geode, and then follow the crack around the geode until it opens. If the geode is hollow, and you know it is hollow, you must be very careful to not strike the chisel too hard with the hammer. Start lightly at first and then strike harder (but not too hard) if a crack is not developing. To see how to open a geode, either view the provided videos or powerpoint presentations below.
Watch a video illustrating the hammer/chisel method to open a large 5 inch Keokuk geode (Windows Media Player File, 4.8 MB size (high speed users)). Windows Media Players should be available for all Microsoft Windows users. If you have problems viewing the video, please contact us if you have Windows Media Player available for use. We plan to add a RealPlayer video soon as well.
Watch a video illustrating the hammer/chisel method to open a small 2 inch Mexican coconut geode (Windows Media Player File, 4.6MB size (high speed users)). Windows Media Players should be available for all Microsoft Windows users. If you have problems viewing the video, please contact us if you have Windows Media Player available for use. We plan to add a RealPlayer video soon as well.
Watch a PowerPoint illustrating the hammer/chisel method to open a 5 inch diameter Keokuk geode (Microsoft PowerPoint file, 480KB (lower speed users)). Most Microsoft Office programs have PowerPoint included.
Videos and PowerPoint presentations are © Copyright 2008, The Geode Gallery. These resources are provided strictly as an educational tools and are not available for distribution without the expressed written consent of The Geode Gallery. Anyone who uses these resources for their own promotional purposes, alters the content, or any other use not for educational purposes is strictly forbidden and will be subject to appropriate copyright laws.
SOCK METHOD: This is the most popular method for smaller geodes that young children break open themselves. Place the geode in a sock and hit very lightly with a hammer. This method is mainly used in groups with kids to protect pieces from flying and potentially hitting someone. Since you are focusing the pressure on the geode in one spot, your chances of having the geode opening in two are not as great compared to the hammer/chisel method, but it is still possible. We strongly suggest this method when having children open the geode themselves for everyone's safety (children have a tendency to swing the hammer as hard as they possibly can!). The hammer/chisel method can be used on all sizes of geodes, so if you desire a geode that is opened into two halves, we suggest using the hammer/chisel method versus the sock method. It may take a little more time but the end result will be worth it.
PIPE CUTTER METHOD: Opening geodes with a soil pipe cutter is a more specialized method, and these tools are usually only found among the more advanced or serious collectors who have a large quantity of geodes to open. Pipe cutters have a chain that contains sharpened carbide-tipped roller blades that is wrapped around the geode and tightened. Unless the geode already has a crack in it (visible or not), the success rate for opening a geode into two nearly equal halves is very high with a pipe cutter and the process is very quick. Pipe cutters, however, are not usually cheap, and that is why they aren't used or available on a widespread basis. The sizes vary, but the most popular type is the soil pipe cutter that contains two arms with equal lengths and a "jaw" with the chain attached. Popular manufacturers are Ridgid, Reed, and Wheeler/Rex, and they can be purchased through most plumbing suppliers (these companies do not necessarily sell direct, you have to go through a distributor). The average price for a new pipe cutter of this variety is anywhere from $300-$600 depending on how long of a chain you want (the longer the chain the more expensive as most of the cost of the pipe cutter is actually in the chain). Some tool rental places also have these available for rent, contact rental businesses in your area for availability if you are opening a large quantity of geodes to justify the cost.
In areas where geodes are abundant (such as the Keokuk, Iowa area), many rockhounds have their own specialized tools for opening geodes. If you are in such an area, we encourage you to contact your local rock and mineral club for more details. Most clubs are more than happy to accomodate you and answer your questions. Virtually any tool that has carbide tipped blades and is designed to cut concrete or rock will also open geodes but make sure the blades are carbide tipped. We have been told that tile wet saws, concrete saws, and other related tools open geodes efficiently as well. SAFETY FIRST! Make sure you know how to operate these tools safely before using them.
I hope this has helped you in opening your geodes! To purchase un-opened geodes, please proceed to the links provided below.
Small (2 Inch and Under) Un-opened Guaranteed Hollow Mexican Geodes Available for Purchase Here
Larger (3 - 12 Inch) Un-Opened Guaranteed Hollow Keokuk Geodes Available for Purchase Here
Return To The Geode Gallery Homepage