All of them are magnetic, and brown from all the rust, are they meteorites???

[Archimedes Plutonium]

[Archimedes Plutonium]

Now most of my rocks are brownish because of the rusting of the iron. But some are massive and dark black without brown. I do not know if any have iridium in them. What would be a test for iridium? I heard that meteorites can have 1,000 more iridium than Earth rocks.

Now that ruler is deceptive for it says mm but the numbers are in centimeters. The manufacturer should have labeled the ruler as CM, not MM.