Zinc has a characteristic light bluish tint and oxidizes to white, not yellow or brown. Some of them appear slightly dull and oxidised with a grey or white layer.
And how do you propose to know how blue-tinted those balls are without being able to tell what they’re reflecting and what the camera’s white balance is set to?
I blurred the image and took a few colour samples; the balls are grey in the image, with very slightly more red in them than green or blue. That doesn’t mean they’re actually grey; they could be slightly blue and reflecting a slightly red scene or vice versa. They could be slightly green but the camera settings have “corrected” it to look grey.
How can you tell that the “dull” ones are oxidised, as opposed to roughened, blurred due to movement or covered with some other substance like lubricant?
All excellent points! I concede to your deeper consideration. (Though I do think that a “roughened” ball bearing would rather prove my point for me, and that those which appear roughened are largely also those under other balls, lessening the chance that they are moving)
Zinc has a characteristic light bluish tint and oxidizes to white, not yellow or brown. Some of them appear slightly dull and oxidised with a grey or white layer.
And how do you propose to know how blue-tinted those balls are without being able to tell what they’re reflecting and what the camera’s white balance is set to?
I blurred the image and took a few colour samples; the balls are grey in the image, with very slightly more red in them than green or blue. That doesn’t mean they’re actually grey; they could be slightly blue and reflecting a slightly red scene or vice versa. They could be slightly green but the camera settings have “corrected” it to look grey.
How can you tell that the “dull” ones are oxidised, as opposed to roughened, blurred due to movement or covered with some other substance like lubricant?
All excellent points! I concede to your deeper consideration. (Though I do think that a “roughened” ball bearing would rather prove my point for me, and that those which appear roughened are largely also those under other balls, lessening the chance that they are moving)