How does cocaine appear on a drug screen?

Cocaine looks llike a fine, white powder, which could easily be mistaken for other white powders.

It looks like crystal rocks and is clear.

NO

Good cocaine is kind of pearly and its not powdery substance if its to powdery its been cut too much

Someone above said, "It looks like crystal rocks and is clear". That is fish scale (that's what it looks like) and is probably some of the purest you will come across. If you want to play, I suggest looking up freebasing.. that'll tell you all you want to know.. God speed