“The diamonds likely aren't fracturing in the application of flattening stones, at least not after its been broken in. “

Of course, they wear, and pull out from the binder. They are hard, but not unbreakable.

They do fracture/wear, ask any good jeweler that looks at a lot of diamonds. People scratch glass with rings and fracture the edges and corners of Diamonds, all the time.

Most folks just don’t ever look at their rings with magnification to see how damaged they are.

Diamonds like any rock or gem are filled with inclusions, especially the lower clarity, use in industrial applications. Here is a quote from an article on Diamond Fracture Filling, a process used to drill out impurities/inclusions from Jewelry quality diamonds to improve clarity, so they can be sold for higher prices.

“Fractures are very common inside diamonds and are created during the diamond's creation in the earth's crust. As the rough diamond travels up from the earth's crust through volcanic pipes it comes under extreme stresses and pressures, and during this travel tiny fractures can form inside the diamond. If these fractures are visible and damaging to the beauty of the diamond, it will have much lower demand and won't be as salable to jewelers and the public, making them candidates for fracture filling and thus visually improve the appearance of the diamond.”

As many of us can attest, they do wear and an Ark, or other hard stones can trash a new Diamond plate in a hurry. So, call it micro fracturing or eroding, they do wear.

Diamonds and how we look and think of them, are in large part a result of an aggressive and successful marketing campaign. Diamonds are not as rare or indestructible as the De Beers, would have you think.