Five Tips for Teaching Rock Identification to Middle and High School Students

Middle and high school students usually have a limited background in rock identification from elementary school. Elementary students focus on the three basic types of rocks and how they form. Middle and high school students can graduate to identifying different rock samples within the three basic types. Students should learn about mineral identification before you move on to rocks, because rocks are simply a combination of one or more minerals.

Tip #1:  Give the students physical samples that they can examine. Hands-on learning methods improve children’s understanding of rock color and texture. Pictures and posters can give students a general idea of sample color; however, only real rocks can adequately teach students the appearance and feel of a rock’s texture. Give students a hand lens to magnify the rock textures and make details easier to observe.

Tip #2:  Explain the three basic types of rocks to the students using actual samples as visual aids.

  • Sedimentary Rocks = rocks formed in lakes, rivers, oceans and deserts,
  • Igneous Rocks = rocks from either underground or above ground from volcanoes,
  • Metamorphic Rocks = rocks that were once a different type of rock but were buried deep below the Earth’s surface and were changed from high temperatures and high pressures.

As you show the samples to the students, choose samples that look very different and also some that look very similar to one another. Middle and high school students are old enough to start noticing the subtle differences between the rocks.

Tip #3:  Give the students identification information cards, sheets or charts that are easy to read with data about the most important properties of the each rock. Mini Me Geology has free, downloadable flow charts that you can use for identifying common rocks. Older students may find information cards or sheets helpful because they can evaluate the sample’s properties and use the process of elimination to determine the rock’s identity. All of Mini Me Geology’s samples come with an information card that give the rock properties such as color and texture plus common locations and uses of the mineral. The Dig Into Geology section of our website has free identification flow charts for sedimentary rocks, igneous rocks and metamorphic rocks. For students who are very interested in additional information about the minerals they identify, a copy of Simon & Schuster’s Guide to Rocks & Minerals, or a similar book, might be fun for them to review.

Tip #4:  Older students should be able to learn to identify multiple samples from each rock category. We suggest the following rocks as good introductory samples for your lessons.

  • Sedimentary Rocks ”“ coquina (made of shells and fizzes with an acid), limestone (fine-grained and fizzes with an acid), shale (fine-grained), and sandstone (coarse-grained and will not fizz with an acid),
  • Igneous Rocks ”“ obsidian (forms outside and looks like glass), volcanic breccia (has two grain sizes from the erupting volcano), basalt (forms outside and is fine grained), and granite (forms inside and has easy-to-see grains),
  • Metamorphic Rocks ”“ gneiss (was granite and can see grains in layers), marble (was limestone and fizzes), slate (was shale and forms in breakable layers), and quartzite (was sandstone and does not fizz).

Tip #5:  Allow your students to work alone or in groups and then before walking through the identification process for each sample. Identifying rock samples helps students develop logical thinking skills that help them in other subjects as well.

If you need help choosing sedimentary, igneous or metamorphic rock samples for your students or explaining the properties of each, you may want to check out our book Help, I Have to Teach Rock and Mineral Identification and I’m Not a Geologist!, which is available on our website.

If you have additional questions, please contact us at and we will help you have a successful rock lesson.


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