Yea, a provocative title - sorry...
While I don't have one of them fancy new modern smart phones that can take pictures of a single grain of table salt, I do have a microscope! And and old digital camera. And, by carefully holding my camera over the eye piece of the 'scope, I was able to take the following 50x photos of new & used filter sand. (Well 50x in the 'scope. Probably several hundred times magnified as displayed.)
So, can you tell which are which, old -vs- new?
Left pics are "Set 1". Right pics are "Set A".
(light source from below)
(light source from above)
Just for fun - a picture of my microscope and phone with a picture of my microscope and my camera with a picture of a slide on the microscope...