....This is really just an explanation for why we can rub off colors, and why they can disappear, or morph....
....Color is light absorbed by molecules, and that which isn't absorbed, reflects back to us in certain wavelengths, we see as color. So, a banana is yellow, an orange orange, etc.
SO, Where does pink salt, red salt, blue salt come from? Pure NaCl is white. Well, From the addition of impurities....
....if you stack the salt hay bales, and some of the bales are a different size and shape, how stable is the stack of bales? They'll still attract somewhat to each other, but, sooner or later the pile will fall over....
....it isn't a huge stretch to imagine our globules of impure Iron Oxide compounds could be disrupted similarly to our simple salt hay bales that have some weird shaped impurities added....
I know you mentioned more to come, so I'll keep a watch for it. Are you thinking of abrasion resistance, or some reaction kicked off by added energy, light?
If I'm not mistaken, it looks like impurities are the key to what happens?
The thought that comes to mind is that heat temper colors are created by iron oxides, the same oxides as in case colors. The temper colors apparently form by differing light reflection based only on the thickness of the iron oxide layer and not impurities. Again, these are likely identical iron oxides as are present in case colors.
Temper colors are generally thought to be quite a bit less durable, rub off easier, than case colors.
If I'm not mistaken, Doc Gaddy's research showed that the stacked globs of iron oxides, as opposed to the flat sheets of temper color iron oxides, were not caused by impurities that disrupted crystal formation. I think he found that a non reacting inclusion, phosphates?, acted as a temporary form for the layering oxides. But, I think he said it was water soluble and went away. I think that's how the random tipping over hay bales are formed?
Anyway, you're probably right about impurities forming color, because as case colors wear, the color doesn't change. But, on the other hand, someones going to have to come up with a reason why impurities clump together to form areas of distinctly different colors. Wouldn't impurities likely mix and dilute, rather than concentrate and separate?
Sorry, I drifted way off the light as an energy source topic.
