Curious Crystals

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Learners carefully look at four known household crystals. After observing and describing the crystals, learners are given an unknown crystal, which is chemically the same as one of the four known crystals but looks different. When learners realize that they cannot identify this crystal by its appearance alone, they will suggest other tests and ways to compare the crystals to eventually identify the unknown crystal. The related activities are examples of tests learners can conduct on the crystals. After a series of these tests, learners will gather enough evidence to identify the unknown crystal. [Activity is publicly available through a web crawler capture on Activity write-up only, images are unavailable.]

Quick Guide

Preparation Time:
Under 5 minutes

Learning Time:
30 to 45 minutes

Estimated Materials Cost:
$1 - $5 per group of students

Age Range:
Ages 8 - 14

Resource Types:
Activity, Experiment/Lab Activity, Lesson/Lesson Plan


Materials List (per group of students)

  • Salt
  • Epsom salt
  • MSG (Accent®)
  • Sugar in cup
  • Kosher salt in cup (unknown)
  • 5 Small cups
  • Black construction paper, ½ piece
  • Magnifier
  • Masking Tape
  • Pen
  • Plastic Spoon
  • Student Activity Sheet


  • Physical Sciences
    • Chemistry
      • Solutions
    • States of Matter
      • Solids
  • The Nature of Science
    • The Scientific Process
      • Asking Questions
      • Conducting Investigations
      • Gathering Data
      • Formulating Explanations

Informal Categories

  • Food and Cooking


To use this activity, learners need to:

  • see
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


Components that are part of this resource:

Access Rights:

  • Free access


  • Kessler, James H. ; Galvan, Patricia M.


  • , American Chemical Society, 2007