Buried rock fragments may be further subjected to processes of weathering that cause them to break down into smaller particles or soil, or they may become new rocks through the sedimentary process. The sedimentary process requires time and pressure to create new rocks from rock fragments and sediment.Know More
Rock fragments are typically small pieces of a larger rock formation that have been broken off through erosion by external forces such as fluctuating temperatures, ice, rain or excessive moisture. These fragments may then be transported to new regions where they are deposited and allowed to settle. Over time, the fragments may be buried by new sediment, which allows the process of lithification to begin due to the weight of the new soil. Lithification involves the compaction and cementation of sedimentary materials, which may lead to the creation of new rocks over time.
The size of the rock fragments and the type of weathering that eroded their source rock can affect the type of sedimentary rocks into which they may form. Conglomerate rocks and breccia are formed from larger sized rock fragments such as boulders and pebbles, which are typically found closer to their source rock formation due to their weight. Finer sediments, such as sand, clay and silt, are deposited further from their source and may form into sandstone, shale or siltstone.Learn more about Geology
While there's no such thing as petrified rock, petrified wood is fossilized wood. According to YourGemologist, there is no wood actually left in petrified wood, only rock that takes the same form and shape of the wood.Full Answer >
Sedimentary rocks are formed by the deposition of mud, clay, sand and other small particles on the surface of the Earth. Sedimentation can occur in many different environments, including lakes, rivers, deserts and oceans. The sediment is deposited in layers that are compressed over time and turned into solid rock.Full Answer >
Marble, which is a type of metamorphic rock, forms from either limestone or dolostone. The formation of marble occurs due to these minerals being under extreme pressure and temperatures. Although the main mineral in marble is calcite, its composition also includes a combination of other minerals, such as quartz, mica and graphite.Full Answer >
According to National Geographic, the main difference between rocks and stones, or gemstones, are their rarity and crystal formation. Most gemstones have a crystal formation, which makes them rare and valuable after they are cut. Rocks usually do not have a crystal formation, which means they are not considered to be of value. Unlike rocks, gemstones are classified on their rarity and value into two categories: semiprecious and precious.Full Answer >