How do rocks get crystals in them?
Jasmine I think you might be talking about geodes, which are a special type of rock that is hollow and has minerals or crystals pointing to the inside when you break them open. First you have to have a hole in some type of rock (usually limestone or the igneous lava rocks, basalt or rhyolite). Then water with dissolved minerals can move through the rock and begin to coat the walls of the holes. After a while, crystals begin to form and grow from the coatings toward the center. Then the host rock weathers away and you find a rounded rock that when you break it open is lined with crystals! Are geodes metamorphic, igneous, or sedimentary rocks? Caroline That’s a good question! Let’s first look at a definition of what a geode is: A hollow rounded rock nodule filled with an inner lining of mineral matter. Sand, water, or petroleum may fill the cavity, or the lining may consist of crystallized calcite, quartz, or other minerals. We should also consider the definitions of the 3 types of rock:
