- A geode (/ˈdʒiː.oʊd/; from Ancient Greek γεώδης (geṓdēs) ’earthlike’) is a geological secondary formation within sedimentary and volcanic rocks. Geodes are hollow, vaguely spherical rocks, in which masses of mineral matter (which may include crystals) are secluded. The crystals are formed by the filling of vesicles in volcanic and subvolcanic rocks by minerals deposited from hydrothermal fluids; or by the dissolution of syn-genetic concretions and partial filling by the same or other minerals precipitated from water, groundwater, or hydrothermal fluids.
- Missouri (Wikipedia)
Missouri is a state in the Midwestern region of the United States. Ranking 21st in land area, it is bordered by eight states (tied for the most with Tennessee): Iowa to the north, Illinois, Kentucky and Tennessee to the east, Arkansas to the south and Oklahoma, Kansas and Nebraska to the west. In the south are the Ozarks, a forested highland, providing timber, minerals, and recreation. The Missouri River, after which the state is named, flows through the center into the Mississippi River, which makes up the eastern border. With more than six million residents, it is the 19th-most populous state of the country. The largest urban areas are St. Louis, Kansas City, Springfield and Columbia; the capital is Jefferson City.