Several processes can turn one type of rock into another type of rock. The key processes of the rock cycle are crystallization, erosion and sedimentation, and metamorphism. Magma cools either underground or on the surface and hardens into an igneous rock. As the magma cools, different crystals form at different temperatures, undergoing crystallization. For example, the mineral olivine crystallizes out of magma at much higher temperatures than quartz.
The rate of cooling determines how much time the crystals will have to form. Slow cooling produces larger crystals.
The small fragments are called sediments. Running water, ice, and gravity all transport these sediments from one place to another by erosion. Their movement often results in earthquakes. Rock Melting.
Metamorphic rocks underground melt to become magma. When a volcano erupts, magma flows out of it. As the lava cools it hardens and becomes igneous rock. As soon as the new igneous rock is formed, the processes of weathering and erosion begin, starting the whole cycle over again! See if you can find sedimentary, igneous, and metamorphic rocks where you live.
As you study them, think about how they have undergone many slow changes to become what they are. Draw a picture of the rocks you find and then draw a diagram of the rock cycle steps.
Keep reading to see how you can experience the rock cycle process for yourself! Wind and water and blowing sand can, over time, rub away the rough edges of rocks, leaving smooth stones. But weathering can happen at home, too! Many people use a rock tumbler to shape and polish the rocks they collect. The results are smooth, shiny rocks. When people tumble gemstones usually semi-precious ones they find , they can end up with beautiful colors and can even use polished stones to make their own jewelry.
A gem or a gemstone is any mineral that can be cut and polished for jewelry or other decoration. The most precious gems are chosen for their beauty , rarity , and durability. Semi-precious gems usually have one or two of these characteristics but fall short in some other areas. Fluorite, for instance, is very beautiful but it is too soft and will scratch easily.
Agate, quartz, and amethyst are other examples of semi-precious gems. Diamonds are gemstones that are considered very precious and for good reason. Though they are made of carbon, one of the most common elements, diamonds are generally regarded as some of the most beautiful gemstones.
They are relatively rare because most diamonds are not jewelry quality. Diamond mines usually have 1 part diamond to 40 million parts other rock.
But a diamond high-quality enough to be in an engagement ring is the product of the removal and processing of to million times its volume of rock! It is the hardest substance found in nature, four times harder than the next hardest natural substance, corundum sapphire and ruby. It also has the highest melting point and conducts heat five times better than the second-best element, silver.
Have you ever made a rock collection? Part of the fun is gathering as many different rocks as you can find. But even though rocks come in many different colors, shapes, and sizes, they all fit into one of three categories based on how they were formed. Learn about the rock cycle steps, the three main types of rocks, and what happens when rocks get so hot that they melt! Unwrap four different-colored Starburst candies. Have an adult use the scissors to help you cut each piece of candy into pieces.
Next, rub your palms together back and forth quickly for several seconds. Be prepared to keep the activity moving and allow for extra clean-up because the crayon shavings can get on the floor.
Investigation Question. How does the rock cycle work? What to do. Skip to main content. Objective: Students will be able to e xplain how heat and pressure affect rocks by making observations of crayon shavings that are placed under heat and pressure. Preparation Before going to the classroom, you will need to: Contact the teacher to find out the length of the class period and the number of students in the class.
Discuss any previous discussions about the rock cycle of understanding of the three main rock types. Alert the teacher that this investigation requires an electrical outlet to plug in the iron see description of materials for clarification and you will need extra safety support with the iron.
Prepare the crayon shavings from 3 to 4 different color crayons by using a hand held pencil sharpener or a pair of scissors to scrape the outside of the crayon like a carrot and a carrot peeler.
Divide about a spoonful of shavings into a sandwich bag, one for each student. The shavings will represent sediments in this investigation. Duplicate the work sheet , with potential modification for grade level. If you are working with Kindergarteners it is important to remember that they will not all be reading.
Describe the pictures rather than using just words so the students know where you are on the diagram. Collect any giveaways for the students, such as fossil posters or geologic time scale bookmarks. Safety This investigation is considered safe to do with students. Investigation Question How does the rock cycle work? What to do 5 minutes Spend the first five minutes getting to know the general geologic knowledge of the class.
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