Types of Rocks (Rock Kit)

Discover igneous, metamorphic, and sedimentary rocks! Learn their properties and how they form.

Take Notes-Fill in the blanks as we discuss in class- 1. Light a. Opaque: When you hold something opaque up to a light source, all light is blocked. This applies to some rock specimens as well as other objects. b. Translucent: When you hold something translucent up to a light source, some light is blocked. Some rocks are translucent even though they may look opaque. For example, tissue paper is translucent - some light shines through, but some light is blocked. You may be able to see bits of light around the edges of one of your translucent rocks because the edges are much thinner than the middle. c. Transparent: When you hold something transparent up to a light source, no light is blocked. For example, glass is transparent.2. Types of Rocks a. Igneous: Form when lava or magma cools and hardens. b. Metamorphic: Form when one rock changes into another as a result of heat, pressure, or both. c. Sedimentary: Form from small layers of other rocks. These rocks settle into layers. After lots of time and pressure, the layers combine to make sedimentary rock. Most fossils are found in sedimentary rock.3. Other Vocabulary a. Mineral: Rocks are often made of minerals - sometimes just one, but sometimes many. Minerals occur in nature. b. Mohs Hardness Scale: A way of measuring a rock's hardness. It runs from 1 to 10, with talc being a 1 and a diamond being a 10. Your fingernail is about a 2.5, so it can easily scratch talc and anything softer. A diamond can scratch anything because it is the hardest substance. c. Streak: The color left behind when a rock is dragged across a white surface. This test helps us to identify some rocks. Interesting Facts In the "Interesting Fact" column, record one thing you found interesting about each kind of rock!In the "Observation" column, record one thing you noticed about each type of rock. Rock Name Interesting Fact Observation Bauxite Coal Dolomite Feldspar Graphite Halite Malachite Marble Pyrolusite Sphalerite Sulfur Talc