Posted: 7/25/2004 2:30:04 PM EDT
| My girlfriend just got back from vacation and brought back this rock and called it a "geode" (sp). She said the lady split one open with a hammer and screw driver but we cant get it to go. Are you really supposed to crack them open or should I cut it in half with a hacksaw? |
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I work in a planetarium and we sell small geodes for $1. They are about the size of a golf ball, or slightly larger. Put one in the end of an old sock, and a good slam with a hammer usually breaks them open. Sometimes you have to hit them a few times though. I've even broken them and had water come out before. |
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I agree with the chisler. If you start whacking a line in a circle around it with a hammer and chisel or old screwdriver, stress cracks will start to work their way through. Give it a few whacks, rotate, and whack again. You'll know it's about to split open when you hit it and the "tone" changes, it will be more of a flat sound as the rock is splitting, instead of the normal hitting sound it was making. Should only take a few whacks after that. It should split cleanly, but as another poster stated, a rock shop can do a nice polishing of the opened edges, where splitting it will look a little rougher. |
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Many geodes are not hollow, but have in fact filled with quartz or chalcedony or the like. If you hit it with a hammer, you're unlikely to have a nice looking specimen. A chisle won't do it either. You need to find a rock shop and let them do it. It's usually just a few bucks. I used to do it myself in the geology lab at school. It only takes a few minutes. Take the time and make your geode nice looking. BTW, what size is it? |