Robby went on a field trip where he mined for minerals. He was so excited that he found real gold because it was yellow and shiny! His teacher asked him to do a test to prove that he had found real gold. He used a ceramic plate and scratched the mineral on the plate. He noticed a greenish black streak on the plate. Robby was diappointed, because gold has a golden yellow streak. He had really found pyrite. Which test did Robby use to determine if he had found gold?
color test
plate test
streak test
or.. scratch test