PLC 2-1 Grade 4 Investigating Little Rocks and Minerals
Background: Sand is rock and mineral material with sizes between .006 and 2 mmin diameter. We can learn much by looking closely at sand. Carefully examining sand for composition, size, rounding, sorting, surface texture of the grains and the kind of organic material provides evidence that may be used to make warranted inferences about how the sand was deposited, how far it traveled, the minerals and rock that make up the sand, and perhaps even the source of the sand’s parent rock material. /
Exploration:
Students should explore the materials, sand and equipment to investigate the sand before formulating questions to investigate.
Pre-Activity Discussion:
  1. Class discussion should focus on students’ experiences with sand. The discussion should provide students with opportunities to share their understanding of sources of the sand and the source of the minerals in the sand. Students should be able to share the understanding that rocks are made of minerals.
  2. The teachers should conduct a discussion with sufficient wait time to allow students to reveal their understanding of rocks and sand. The teacher should apply concepts of “Talk and Argument” and extending thinking from chapter 5 of RSS. The teacher should focus assessing student understanding of the concepts and student understandingof how sand is used by people.
  3. Discussion questions might include:
  1. What is sand made of?
  2. How might we investigate sand to determine what it is made of?
  3. Is all sand the same?
  4. How is sand formed and where does it come from?

Starting Procedure:
  1. Place a pinch of sand on a clean surface.
  2. Use a magnifying glass to investigate the appearance of the constituents of the sand.
  3. Use a toothpick to sort the crystals into separate piles based on criteria students select.
  4. Use an information source to find additional information on minerals and/or rocks.

Investigating Independent Variables:
  1. Take three or four measures from a sample and compare the relative amounts of the various minerals.
  2. Compare samples from various locations.
  3. Design and investigate an independent variable.

Question 1: What are the differences between the various grains of sand in your sample?
Question 2: What is the relationship between the amount of various minerals in the sample and the source of the sand sample?
Questions 3: What are some warranted inferences that can be made about the shape of the sand particles?
Conclusions/Inferences: / Evidence:
Teacher Notes:
The discussion should focus on students revealing their understanding of the attributes of sand that can be used to classify the particles. Some teachers use this activity to lead into rock collections glued to a 3x5 card. These collections must be seen using magnifying tools. The activity should focus on students investigating the materials and making warranted inferences. They may be able to discuss variables such as sample size, source of sand, and other variables. At a minimum, the 10X loupes are needed to see the sand well.
It may be effective to assign different sands to different groups and have the student jigsaw.
It is important to provide time for exploring (playing) the tools and the sand to prepare for an investigation.
The outcome of the investigation should be an investigation with an independent variable.
EXAMPLES:
  • What is the relationship between the source of sand and the shape of the particle?
  • How does the hardness of a particular rock sample affect the relative amounts of sand of various sizes in the sample?
  • What are the difference between sand collected at ______and sand collected at ______.
  • What is the relationship between the composition of parent materials and sand?

Standard Operating Procedures:
Sand samples should be labeled and placed on tables in different corners of the room.
Magnifying glasses, toothpicks, and other materials should be placed in two tables separate from the samples.
Provide trays and paper towels to aide in cleanup of sand.
Encourage students to label the samples.
Have students explore the sand before designing the investigation.
Resources on the Web
Sands of the World
Utah Science Core Curriculum
Standard 3
Objective 1: Identify basic properties of minerals and rocks.
  1. Describe the differences between minerals and rocks.
  2. Observe rocks using a magnifying glass and draw shapes and colors of the minerals.
  3. Sort rocks by appearance according to the three basic types: sedimentary, igneous and metamorphic (e.g., sedimentary–rounded-appearing mineral and rock particles that are cemented together, often in layers; igneous–with or without observable crystals that are not in layers or with or without air holes or glasslike; metamorphic –crystals/minerals, often in layers).
  4. Classify common rocks found in Utah as sedimentary (i.e., sandstone, conglomerate, shale), igneous (i.e., basalt, granite, obsidian, pumice) and metamorphic (i.e., marble, gneiss, schist).

Materials:
Sand from a variety of sources
Toothpicks
Magnifying Glasses
Classification Key / Scotch tape
Card Stock
Measuring tools (5-20 ml)
Screens to sort the sand by size