I have to utilize a Curve Tracing machine on a 5V Zener Diode for a lab. The curve tracer shows voltage vs. current. The lab asks me to examine the curve and determine whether it is a Silicon or Germanium diode, but I'm wondering.....what would be different about the graphs of the two types? Wont they both have a shoulder near -5V? Oh yeah, I only get to do it reversed biased, as it doesn't show 4 quadrants worth of graphs. So I can't look at the shoulder for forward biased. Is there a trick or is the question a trick?