Earth Science Activities - Rock properties; Inquiry Process - Classification, observation, evidence, and reasoning to understand. (1st - 2nd Grade)


This investigation explores rocks, their properties, and different ways to classify rocks. (Sample rock pictures)

Concepts and outcomes

Content - Earth Science - Rocks and their properties

What we learn with science - enduring understanding, big ideas, generalizations

Rocks are composed of Earth materials.

Related concepts and facts

  • Rocks are composed of Earth materials - sand, silt, humus (leaves, plant parts, animal parts, microorganism), gravel, rocks ...
  • Rock properties include luster, hardness, color, mass, density, crystals and if present their size,


Describe properties of rocks.

Specific outcomes

  1. Identify common properties of rocks (color, hardness, crystals, grainy, size, luster).
  2. Describe rocks by their properties.
  3. Identify rocks by common properties.

Inquiry Processes

Observation and properties

How science explores and uses observation and properties to understand and explain.

Observation can be used to identify properties to describe characteristics of objects and objects themselves.

Related concepts and facts

  • Observation can be used to identify properties of objects.
  • Objects have many properties.
  • Objects can be described and compared by properties.
  • Properties are size, color, shape, texture,


Make observations, identify properties/ characteristics and use them to describe objects.

Specific outcomes -

  1. Describe an object by its properties.
  2. Describe the term - property and provide at least two examples (color, hardness, texture, luster, crystal, mass, size, shape, temperature, amount, volume, rate, ...
  3. Recognize that some properties are necessary to include when describing an object.
  4. Recognize that a sufficient number of properties needs to be included to describe an object.
  5. Recognize a unique set or properties is required to distinguish a unique object.

System, order, organization - classification

Properties can be used to organize objects as similar or different and into groups with similar properties (classification).

Related concepts and facts

  • Properties/ characteristics can be used to group objects.
  • Objects can be grouped by similar properties/ characteristics.
  • Classification systems can be changed by changing the properties/ characteristics used to group the objects.


Group and regroup rocks based on observed properties.

Specific outcomes

  1. Classify objects by their similar properties or characteristics.
  2. Create a classification system to classify rocks.
  3. Modify their classification system to include additional properties
  4. Use their classification system to classify unfamiliar objects (rocks).
  5. Group and regroup rocks based on observed properties.
  6. Students will suggest a classification system, that operates like the one created and used for rocks, could be created and used to classify animals or plants or other things with many properties.

Pedagogical ideas

Activity Sequence

  1. Observe different rocks and group. Draw and record observations with explanations as to similarities and differences.
  2. Discuss how the different properties such as luster, hardness, can it be sanded, are there crystals?
  3. Introduce other properties, how to determine a range for those properties, and model how. Then provide additional rocks and have students group or regroup the rocks.
  4. Visit a place with different rocks, determine how they are grouped, and have students compare that grouping to one of theirs.

Focus questions


Activity 1 Exploration


Learners bring rocks from their neighborhood, supplemental rocks to observe, plastic knife, piece of glass, magnifying glass, tray for rocks,

  1. Students brings some rocks from their neighborhood to put into a mixed collection or rock samples for the class.
  2. Divide the rocks onto trays so each science group has about ten rock samples. Also include a magnifying glass, items to use for a scratch test (plastic knife, glass, ...)
  3. Students make and record observations of the rocks (use all senses, but taste).
  4. Ask students to decide which belong together.
  5. Group them and describe what criteria they used to decide in what group to put each and record it on a note card.
  6. Have groups share their groupings and criteria for each.
  7. Have group compile a list of properties they used to classify their rocks. (color, size, weight, texture, crystals, hardness, chemical makeup, other)
  8. Have students put each group of rocks into a separate box.
  9. Have groups share how they combined the properties to create the classifications they used.
  10. Have groups regroup their rocks in light of what other groups may have reported.

Activity 2

  1. Introduce properties that they did not use and discuss how they might be considered as variables (any from above, fracture, crystal grain size, density, or other).
  2. Model how to determine ranges for different rock properties.
  3. Ask if the additional properties should be used to create a better system.
  4. Have students create a more complex classification system.
  5. Have students share a variety of complex groupings.


  1. Provide additional rocks students haven't observed before and have them tell how they would fit into their classification system.
  2. Have them write their responses and share them with the class.

Activity 4

  1. Visit a museum or invite a geologist or jeweler to share related rock and classification system ideas.
  2. Describe rocks as ...


Lab Notes

Rock properties.

Rock properties Comments


































Dr. Robert Sweetland's notes
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