Chemists... help?

When I was younger, I wanted to be a biochemist. Somewhere along the way, I changed my mind, but the building blocks of this world have always intrigued me.

Which is part of the reason why I was stunned to find this in my trunk:

Originally, this was an ordinary bucket hook (which I believe is made from stainless steel); however, at some point a couple of days earlier, bleach spilled in one of the plastic containers in the trunk—making contact with a baking soda air freshener that I keep back there to curb the smell of gasoline, paint thinner, and other undesirables for a vehicle. This unknown compound is what resulted. It almost seems like rust, but of a different, spikier structure. I am highly curious as to what exactly it is.

And so, to the more hard-science minded than I,
Any ideas?