What destroys a diamond?

Most diamonds that are mined -- 75% -- are employed by industry, because diamonds are harder than any other known mineral.

Over time, because of the flaws in formation of these stones, they may begin to separate at the weakest points -- the flaws -- so that the implement becomes less sharp and able to perform as expected.

In diamond-tipped hand-tools, this process probably takes several lifetimes, automated machine-driven tools, less time.

A gem-quality diamond without any flaws -- an expensive diamond -- could be melted if you could heat it to 3820 degrees Kelvin or 3546.85 degrees Celsius or 6416.23 degrees Fahrenheit.