What Is A Geode Rock

The only difference between a geode and a nodule is that a geode has a hollow cavity and a nodule is solid.

What is a geode rock.

Geodes derived from the greek word γεώδης meaning earth like are geological secondary formations within sedimentary and volcanic rocks geodes are hollow vaguely spherical rocks in which masses of mineral matter which may include crystals are secluded. So compare the weight of the rock you think might be a geode with another one of the same size. Rocks which are completely filled with small compact crystal formations such as agate jasper or chalcedony are called nodules. In ohio a large geode called crystal cave is open for tours.

What you want to do is check the weight. These rocks may range in size from a few centimeters to several meters in diameter and they come in many different shapes including spheres ovals oblong blobs and irregular masses. Geo means earth and these amazing rocks. Shells tree branches roots and other organic materials often decay away to leave a void for the formation of mineral materials.

Except for being kind of roundish there isn t much remarkable or interesting about them. This can make geodes hard to precisely identify as whole rocks for the beginner. This celebration of geodes does not stop with iowa. Geodes can also be embedded inside another rock layer such as limestone.

From the outside a geode looks like an ordinary rock. A geode is a rock with a special surprise inside. The only true way to know if a rock is a geode is to crack or cut it open and find out if it contains a crystal core. From the exterior a geode appears to be a boring round shaped rock with little to capture one s attention.

Iowa a state known for its geode deposits has the geode as its state rock officially designated in 1967 and has a state park called geode state park. The crystals are formed by the filling of vesicles in volcanic and sub volcanic rocks by minerals deposited from hydrothermal. Since geodes have hollow spaces in the middle they will weigh less than other rocks of the same size. Geodes in sedimentary rocks are usually found in limestones dolomites and calcareous shale in these deposits a gas filled void can serve as the opening for geode formation.

Geodes are like the tootsie roll pop of the geology world because underneath the hard exterior lies a surprise center. The term geode is derived from the greek word for earthlike and refers to a hollow rock with a crystal lined cavity.