The diamond may be the hardest known substance on earth, but it still requires attention and care. Daily exposure to perspiration, pollution and household chemicals can dull a diamond's surface.
The good news is that a little periodic scrubbing with a soft-bristle brush in a warm, soapy solution will restore your diamond's sparkle. Also, periodic ultrasonic cleanings and spot-checks by your jeweller will help keep your gem radiant.
Only a diamond can scratch another diamond. Storing them in individual cloth pouches will protect diamonds from each other, and prevent the diamonds from scratching or dulling other jewellery.