Streak Test

3.7 based on 50 ratings

Updated on Oct 30, 2013


You can’t always tell what mineral you’ve got by its color; lots of them look alike. How can you tell them apart?


  • Set of 8 mineral samples: amethyst, azurite, calcite, lodestone, mica, rose quartz, talc, pyrite
  • Streak plate
  • Pencil
  • Paper


  1. Write “Sample” in the upper left-hand corner of the piece of paper and make a list of the name of each mineral sample below it.
  2. Now create another column headed “Specimen Color,” and a third column labeled “Streak Color.”
  3. Pick up the first mineral sample on your list, and in the Specimen Color column, write down what color it is.
  4. Hold the streak plate in your other hand and try to draw a line on it, pressing hard. Be careful, some samples may be harder than the streak plate, and if they are, the “streak” you’re seeing will actually be powdered streak plate! Try to rub away some of your streak. If the scratch plate is scratched underneath, what you’ve got is a scratch and not a streak.
  5. Write the color of the streak in the Streak Color column. If there’s no streak, write “none.”
Michelle Formoso is a mom and library sciences student at San Jose State University.

How likely are you to recommend to your friends and colleagues?

Not at all likely
Extremely likely