KEY WORDS ROCK CYCLES FULL

If the formula equals less than 2.7, the geode will be more hollow and have more crystals inside.If the formula equals 2.7, it is likely the geode is solid quartz.The specific gravity for a geode is 2.7.Weight of displaced liquid = weight of the object.Formula for specific gravity: W(air) / (W(air)-W(water)).To do this, calculate the specific gravity of the geode. We can use Archimedes’ principle to figure out whether a geode is solid or hollow. Like the Archimedes’ crown, a geode is an irregular shape so it is hard to measure the volume.

Video credit: “ How taking a bath led to Archimedes’ Principle” by Mark Salata/ TED-Ed is licensed under CC BY-NC-ND 4.0 Watch the video, below, for an explanation of Archimedes’ Principle.

A geode that is less dense will have more crystals inside, which is usually the kind of geode you see cut open. In class, we apply Archimedes’ Principle to figure out how dense a geode is. Different minerals form different types and colors of crystals inside the geodes.Īrchimedes’ principle says that the weight of the displaced liquid is equal to the weight of the object. Once these rocks are hollow, or at least semi-hollow, various minerals are able to seep in through the rock’s microscopic pores, creating crystalline structures over long periods of time. In other cases, organic material, like a piece of wood, gets buried in the sediment and eventually weathers over time, leaving behind empty space. Then, a period of deposition occurred where mineral infused water penetrated the permeable surface and began filling the geode with quartz. In this time, the believe is that a more dense object carved out the cavity from the inside, like a shell moving around and gouging out the hollow space. In these particular rocks, the leading theory is that after deposition there was a period of erosion. However, cavities can also form in sedimentary rocks, such as limestone and sandstone, which produce the geodes we find in Iowa. Sometimes the outside of the melted rock cools before the inside, which becomes brittle and breaks a little bit due to the weight of the liquid inside. Another possibility in which a cavity can form occurs when lava solidifies under water. As the molten rock cools and the gas dissolves, an empty space is left behind. One way a cavity can form occurs when a bubble of carbon dioxide and water vapor forms in flowing lava.

KEY WORDS ROCK CYCLES FULL

Full copyright statement found here.Ī geode forms when a cavity forms in a rock, which can occur in different ways.

Can melt and become magma and igneous rockĬopyright © 1999-2003, Wheeling Jesuit University/Center for Educational Technologies®.Can undergo heat and pressure to transform into another metamorphic rock.Can melt and become magma or igneous rock.Then, these sediments can be compacted again into sedimentary rocks. Can undergo weathering and erosion, thereby breaking apart into sediments.Then, it will cool and re-form as an igneous rock. Can undergo weathering and erosion to become a sedimentary rock.Can undergo heat and pressure to become a metamorphic rock.Each type of rock can undergo different changes that affect its form and the type of rock it is. The key processes in the rock cycle are heat & pressure and weathering & erosion. When magma cools in water or on the surface of Earth, like after a volcano erupts, it cools more quickly and forms smaller crystals. Since it is inside Earth, it is well protected and forms larger crystals. When magma cools underground, it cools more slowly. The word metamorphic means to transform or change shape you may have heard the term metamorphosis–the process in which a caterpillar transforms into a butterfly.Fossils are always found in sedimentary rocks.The early Earth was made of liquid magma that then cooled to form solid rocks, so this was the first type of rock.formed when existing rocks undergo extreme heat and pressure.formed when many small particles called sediments are compacted together over time.Rocks are classified as three types: Igneous, Sedimentary, and Metamorphic.

Key words rock cycles