Geode

Geode with a window

Personal Note: Whereas Geodes themselves are technically not a mineral, the properties of the mineral inside them still occur. Most of the solid ones are filled with Agate or Jasper and the hollow ones usually contain some type of Quartz.Although the shape of this geode is a little unusual, it was such a pretty one to post here.They have a matching pair of these in Dillon, Montana in their Mineral Museum.They're called the Maiden Sisters or something like that.The most distinguishing occurance with geodes is that most of them are exceptioanly round. They are round because the minerals solidify in gas pockets, which are naurally round within the hot lava.

Geodes are filled with solid minerals like Agate, or hollow, filled with crystals growing inward.(Like the big bubble gums).You really can't tell just by their outward appearnce. They all are really round with a rouch crusty surface.The minerals in the area, geographical occurances, and how fast the Lava cooled. You have to learn by expereince to guess which is which.You'll learn by if a rock is bigger but weighs less than a smaller one; the larger one may be hollar with the heavier being solid.Both the hollow and the solid centers are treated a little different.If the center of the large ones have crystals, you want to break the Geode in half.If you feel your Geode is solid, then you'd want to have a nice smooth slice down the middle.Many people use these mataaching peices as book ends.