indoor range lead oxidized with different colors?

[mac1911]

157738157739 I smelted this lead a few years ago from a indoor range clean out. dug it out to cast some shotgun slugs and found this. I have other lead that has tarnished or oxidized but not this color? any ideas. it was stored out doors for some time. but even my lead sheets that are exposed to the weather don't look like this? all the pans used where aluminum

[rmark]

I have a 5 gallon bucket of COWW ingots that have the same brown exterior. I don't know why. Mine were smelted in a cast iron Dutch oven.

[mac1911]

I,have used the same cast iron pot for smelting. Only this range lead. ( I cleaned out the range personally) has this tarnish. Everything else I have turns shades of grey

[JonB_in_Glencoe]

looks like rust (iron oxide). were they stored with steel ? in the rain?

Oak leaves ? as in tannic acid.

[mac1911]

looks like rust (iron oxide). were they stored with steel ? in the rain?

Oak leaves ? as in tannic acid.

High possibility there. I have oak trees all over. I had this,lead out side for a few years. Never in standing water but the crate does have holes. think jumbo milk crate with solid cover.
Thank you