How to tell crystalline from amorphous on touch?

[RandomGuy1]

Apologies if this is a stupid question, my basics are really weak. We have Inorganic Qualitative Analysis in our chemistry syllabus and I have somehow never been able to figure out if a substance is crystalline or amorphous. They both feel so ... powdery.

 

[Borek]

There is no way to tell just by touch.