I'm watching Superman 2 on Syfy and I have sometimes wondered what was that red crystal rod that Zod broke? Based on the "S" on the front of it I assumed it was something of Jor-el's. Was it something really important or was it a "honey pot" to draw Zod and his "gang" out to arrest them and put them on trial?
There's nothing to indicate exactly what it is, but the screenplay seems to indicate it's somehow related to Jor-El's role with the council (emphasis mine)
ZOD leads the way into the chamber. This imposing crystalline space, the parliament of Krypton, is empty for the moment. But the signs of its members are ever-present: around the great floating slab that is their conference table each has his (or her) own console of crystals - a transparent container marked with the identifying insignia, c.f. the symbols on each of their robes in Part I.
As Non and Ursa follow two paces behind. Zod strides along the slab, ignoring console after console, stopping only when he reaches the one emblazoned with the S-like crest of Jor-El.
ANGLE DOWN ON IT as Zod lifts the lid of the console and removes, from among all transparent crystals, the one red crystal.
PAN UP as he lifts it high. It glows even in the dim light of the empty chamber - until Zod, with a satisfied and sinister smile, snaps it in half. He tosses it to the ground and looks with a self-congratulatory air at Ursa and Non.
Given that they are tried and condemned immediately afterward, it's likely it was the final piece of evidence in Zod's scheme to overthrow the council. In other words, it's just a MacGuffin so they can tie the trial of Superman I into Zod being the villain of Superman II.