When crystal isn't crystal-clear, try a few methods to restore its clarity and sparkle. Soak, scrub or fizz away the foggy residue that's leaving an opaque film on the glass.

Cloudy Crystal

A common reason for foggy or cloudy crystal is dried calcium deposits on the inside of the glass. These are left from the calcium and magnesium ions in hard water that result from:

  • Flowers left too long in evaporating water in a vase.
  • Dishwasher residue.
  • Washing crystal in hard water and letting it air dry.
  • Complex shapes cleaned in the dishwasher may retain a film of milk, egg or detergent if the rinse spray can't reach inside a bowl. The water is so hot it "bakes" on food film, or the water is so cool it leaves grease on theglass.

Etching is a more serious condition -- microscopic scratches left in the glass surface by phosphates in combination with "soft" water. This surface erosion or pitting is harder to remove than hardened film because the surface of the glass must be re-polished.

Clearing Away the Fog

A number of remedies may dissolve the film on the glass and restore your crystal's shine. First, never wash good crystal in a dishwasher. Wash it by hand with mild soap and water; rinse and dry it immediately with a lint-free cloth. Tackle a buildup with chemicals.

  1. Clear a work area; set a soft towel under the crystal to prevent chipping, and fill the glass with warm water and drop in an effervescent tablet such as a denture or antacid tablet and let the bubbles loosen and release the deposits. Then rinse; wash with mild detergent and water; rinse again and dry.
  2. Try the same trick with baking soda and white vinegar -- add a tablespoon or more of baking soda to warm water in a vase or glass. Pour in vinegar and let the resultant fizz do the work.
  3. More stubborn deposits may need an ammonia bath -- leave an even mix of ammonia and water to eat away at the cloudy stain for a few hours.

Swab and Soak Solutions

Sometimes the fog won't lift, and you have to get more aggressive.

  1. Use protective gloves for your hands and swab the cloudiness with nail polish remover on a clean cotton pad. Then wash the piece thoroughly with soap and water before rinsing and drying.
  2. A paste of 1/2 tablespoon of salt and white vinegar, rubbed on with a soft cloth and allowed to sit for 10 minutes or so, might do the trick. Lightly work off the film with a soft bottle brush before cleaning the crystal.
  3. A dab of whitening toothpaste rubbed on with your fingertip might do for your glass what it does for your teeth -- rub in a circle and don't grind the mild abrasive into the glass.
  4. Fill the sink or basin with a towel, to prevent chipping, and undiluted white vinegar, and submerge the crystal for 30 minutes or more.
  5. Try a home remedy of vinegar and water with crushed eggshells or rice as a scrubbing agent to lightly "sand" the inside of the glass.
  6. Apply an acidic cleaning agent designed to remove limescale from the tub -- test a minute amount of this first to avoid damaging a fragile piece of glass. Rub very lightly in small circles.

The Big Guns

Really set encrustations of calcium and other deposits that cause crystal to become cloudy may require the services of a professional to clean the foggy glass with a very dilute solution of muriatic acid and water. Glass that has been etched, resulting in a dulling surface erosion, may be polished to delicately grind down the pitting to a smooth shiny finish again, another job for an expert who will help you preserve valuable or sentimentally important crystal.