If Iridium, Uranium, Osmium, Sulfur, Zeolite, or Pulsar Quartz are picked up (not mined or crafted), will it reappear at that location? If they appear, how many in-game days must pass for this, or how many minutes / hours of real time?

There's no respawning. Once you've collected them all the only way to get more if from mining. Occasionally from meteor storms. And for 2 of them from rockets.