Hobbies And Interests
Things You'll Need
Instructions
Determine if you have a rock or mineral. A mineral is a single substance and a rock is made of one or more minerals. If your sample has at least two colors or grains that look different in texture or sheen, you likely have a rock.
Examine the properties of the mineral or of each of the minerals in your rock sample. Record the properties of color, streak, hardness, cleavage and crystal shape. The streak is the color of the mineral in powder form which appears when you scratch a mineral on a streak plate. The Mohs scale is a relative hardness scale used to determine the hardness of a mineral. A mineral sample has cleavage if it splits along smooth surfaces when broken with a hammer. The Utah Geological Survey website provides details about these mineral properties.
Review the Utah reference book or geology websites for photos and descriptions of minerals which match the properties that you identified in your sample. It is likely that you will identify more than one potential name for a sample. The reference book or website may provide additional details on the mineral which you can then test. For example, halite and calcite samples that are not perfectly formed look alike; however halite tastes salty and calcite will fizz if a drop of acid drips onto the sample.
Use the names of the minerals that you identified in your sample to determine the name of your rocks. Rocks are a mixture of minerals that have a distinct texture. Some rocks can have the same mineral combination but will have a different texture. Use the Utah reference books and websites to help you match the sample you have to known rocks that are mined in Utah.