Nope! A diamond is the hardest substance on earth so only a diamond can scratch a diamond!
Diamond will scratch anything.
diamond
A diamond can scratch a diamond, but one diamond cannot scratch itself.
No as a diamond is significantly harder then any knife material thus trying to do so would likely result in the knife edge being ruined. Although softer then diamond, this is the same reason granite or stone cutting boards shouldn't be used.
No. Only a diamond can scratch another diamond.
gympsum can scratch diamond
A diamond will scratch anything and everything, including another diamond.
No. Diamond will scratch steel, however,
it can scratch fluorite
Yes, in fact, it is the only way to scratch a diamond.
Yes: not a good use for a diamond, but yes, a diamond will scratch a nail.
Diamond is harder than steel: you can scratch steel with a diamond, but steel will not scratch a diamond.