Geodes: Crack or Saw??

 

 

 

A lot of geodes we sell are beautiful whether you crack them, saw them or leave them whole. The most important information I can share with you today is that breaking open a rock that is millions of years old is bound to surprise you in some way.  Keep this in mind, because no one knows what is inside this ancient rock until it is opened.  Think of it as Mother Nature’s Art…each one is different and it was created just as it was supposed to be.  These grand geodes have endured some of the most cataclysmic events in their lifetime and have metamorphosized into what we call a geode.  Have fun with it and enjoy natures beauty.

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Most Colleges/Universities have Geology Departments, and most Geology Departments have diamond saws for cutting rocks. If you'd like to saw a geode or agate, give the local College/University a call...believe it or not, they LOVE cutting rocks for people. 

- One way to open a geode is the old-fashioned way........with a hammer! A rock hammer or plain-old carpenter's hammer will work for small geodes and a sledge hammer for larger ones. 

If you choose to hammer your geode open.  Look at your geode and see if there are any existing cracks or natural indentations. Start with light taps, and build your way up. You only want to use enough force to start a crack, not shatter it into several pieces.

If you have a lot of Geodes to open, a tool we suggest using is a soil pipe cutter. These are plumber's tools, and can be bought online, or at some plumbing supply warehouses. Some models are manual, and others are hydraulic.

Another suggested purchase is a lighted Jewelers loupe.

Remember your Safety glasses and gloves and Have Fun!

 

 

The overall best way to open a geode (and most particularly, an agate) is to saw it. Diamond rock saws made just for this purpose can be bought at rockhounding supply stores, and Ebay, online. You might even find one for sale locally on Craigslist.

 

 

Shown here are pictures of geodes we have both broken, and sawed. The broken geode is a quartz geode and the sawed geode is a red geodes like you may have seen in our Ebay store.

 

Quartz Geode Cleaning Techniques

 

Some geodes are opened with sparking clean quartz crystals and maybe some secondary minerals are present while other geodes are opened and they are filled with mud and /or the crystals are stained with dissolved minerals from being exposed to the elements for millions of years.  Mother Nature has taken over but there is still hope for these geodes with proper cleaning techniques. We will list several ways and you can decide on what is best for your geode. To the right....We have illustrated through pictures of what a geode may look like during the process.  This particular process took 5 days with multiple cleaning techniques.  You can spend more or less time detailing your geodes to bring them to shelf quality.

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Water - Hose off you geode and enjoy its sparkle. Use the Water Pik option to detail your Quartz.

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Super Iron Out - sodium dithionate

1st solution for Iron staining and to clean residue due to dissolved minerals.  Easy on the environment and no need to neutralize solution before disposal.  Follow directions on the container.  The process can take days to weeks. The solution is only good for a few days and it may require multiple batches to be produced.

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Hydrochloric Acid or Muriatic acid – swimming pool acid or concrete acid

Fast acting aggressive acid that requires much safety precautions.  Eyewear, chemical gloves, and proper ventilation are essential.  This is the most aggressive method; protect yourself if you go this route.  Be aware this acid will dissolve away most secondary minerals to quartz to include calcite, dolomite, and other alkaline minerals. Do a test to make sure you want to use this method.  Only use plastic containers or buckets. If you dilute the acid, ONLY add acid to water, not water to acid.  After a bath in acid for 5 minute or up to 5 days, dip in clean water then you will need to soak your geode in baking soda and water to neutralize the acid on your geode the water will fizz and continue cleaning out the acid.  Then rinse and soak in clean water change water several times. If there is still clay, rocks, or mineral residue left on your geode, you can use a water pik to clean out your geodes cavity and rind.  This process can take up to a week to complete. You can place the lid on the bucket to prevent children and animals from exposure (but provide a small vent hole for relieving gas pressure). To fully neutralize your old acid add baking soda, when it no longer fizzes then you can dispose of the acid safely.

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Oxalic acid - white crystalline powder (Bar keepers friend, Rainbow –wood bleach)

Oxalic acid is easy to find, use and the safest for the home. It is used to dissolve the iron oxide (brown) stain on all minerals. Fill a plastic one gallon container 3/4 full with distilled water. Pour in the OA crystals and stir for five minutes. Be careful not to inhale any powder when adding the crystals. Once the OA is dissolved top off the container to a full gallon. Label the container and put out of reach of children or pets. Set aside for several days. Preferably outside where the sun can heat it up, heat speeds up the reaction. You can reuse the solution over and over. As it dissolves more and more iron it will get darker often taking on a green color. After it gets really dark I would discard it and mix a new batch. Safety is important. OA solution is highly toxic. It can be absorbed through the skin and builds up in your organs cumulatively. Same goes for the fumes, which is why you never boil the solution and always have proper ventilation when using. After the iron color has disappeared then you can remove the specimens (with gloves on) and wash under running water for three hours. NOTE: If you have hard water in your area, it is smart to use distilled water for the first few rinsings to prevent the formation of insoluble oxylates that will stain the specimen when dry. Then soak in clean water for a day changing the water as often as possible. The best formula for washing minerals is:

• Change the water every minute for an hour.

• Change the water every hour for a day.

• Change the water every day for a month.

The best way is to place the rocks to be washed in a 5 gallon bucket. Drill a small hole in the bottom, then fill with water and adjust the flow of the water trickling in to equal the flow out through the small hole. Acid is heavier than water. It will settle to the bottom and flow out through the hole. The trickle in ensures that all specimens are covered with water.

 

Bleach - If your Geode has organic material on it, like algae, use household bleach to clean it. Be sure to let it dry for a day before using any acid cleaning method.

 

Vinegar – A light acid

If your quartz crystals are encrusted with calcite, barite, or lime carbonates, you can try cleaning them with ordinary household vinegar and washing ammonia. You'll want to soak them for 8-12 hours in full-strength vinegar. Wash the crystals well, and then soak them for the same amount of time in washing ammonia. Rinse them well and wipe dry. If this helps remove the coating, but doesn't finish the job, you can try repeating the process a couple of times.

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