Collecting quartz crystals can be a fun hobby for any gem enthusiast. However, they often come covered in various other minerals that stain the beauty of the crystals. You can typically clean these stains off yourself using a variety of methods – from scrubbing to chemical cleaning.

Part 1
Part 1 of 3:

Removing Minor Tarnish and Stains

  1. 1
    Use an old toothbrush. If you have just a few quartz crystals or crystals that are only slightly tarnished by clay, you can use an old toothbrush to clean them off. Simply wet the toothbrush with water and scrub the quartz crystals in your hand.[1]
    • You can even use scouring powder and a steel brush for tougher stains, as quartz is a very durable material.
  2. 2
    Dry the quartz crystals in the sunlight. If your quartz crystals are covered by a large amount of clay, you can place them outside in indirect sunlight for several hours to let the clay dry and crack. Once the clay is sufficiently dry, you should be able to brush off the remnants.[2]
    • You may need to repeat this process several times.
    • Be sure not to place the crystals in direct sunlight because this could cause them to heat up too quickly and become damaged or cracked.
    • This method will only work to remove dried clay from your quartz crystals. If the quartz is covered in iron deposits, you’ll need to use an oxalic acid method.
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  3. 3
    Remove iron stains with a high pressure water tool. Most iron stains can be removed with a high pressure water gun. Simply shoot the water spray at the quartz crystal and watch the stains disappear. This will work for most iron stains on your quartz, leaving only some slight staining in the cracks of the crystal.[3]
    • You can also try removing many of the iron stains with a high pressure air tool.
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Part 2
Part 2 of 3:

Removing Deposits and Tough Stains

  1. 1
    Soak overnight in oxalic acid to remove iron deposits. If your quartz crystals have only a small outer layer of iron, you should be able to thoroughly clean them by soaking them in a weak solution of oxalic acid overnight. Put the quartz crystals in a plastic bucket with the oxalic acid and cover the bucket overnight.[4]
    • You can rinse the crystals with a garden hose or in the sink the next day. Be sure to stopper the sink so that you don’t lose any of the crystals.
    • Oxalic acid can be purchased from most drug stores in powder form.
  2. 2
    Remove stains by soaking in a store-bought solution. You can purchase a cleaning solution called Iron Out at most home improvement or household stores (like WalMart). Simply soak the quartz crystals in the cleaning solution and watch the stains disappear. You may have to let the crystals soak for days or even weeks for them to become completely untarnished.[5]
    • Be sure to rinse the quartz crystals with water when you finish.
    • If you want to make your own Iron Out cleaning solution, you can combine 33 grams of sodium dithionite, 28 grams or sodium bicarbonate, 59 grams of sodium citrate, and 800 milliliters of water. Simply swirl the mixture around until all of the chemicals are dissolved in the water.
  3. 3
    Remove algae deposits by soaking the crystals in bleach. If your quartz crystals are covered in algae deposits or other minerals, you can try cleaning them with household bleach. Soak the crystals in a bowl filled with water-diluted bleach and let them sit for several days.
    • Be sure to rinse the quartz crystals well after taking them out of the bleach solution.
    • Let the crystals dry thoroughly (for at least one day) before you begin any other kind of chemical cleaning.
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Part 3
Part 3 of 3:

Taking the Proper Precautions

  1. 1
    Perform the cleaning in a well-ventilated area. Whenever you are cleaning quartz crystals with oxalic acid, you need to do it in a highly ventilated area. These fumes can be very harmful to you if you inhale them. Acidic fumes can be poisonous to animals and humans.[6]
  2. 2
    Wear gloves when handling any type of acid. In addition to being harmful if inhaled, acid can burn you if it comes into direct contact with your skin. Be sure to wear rubber gloves when handling oxalic acid and while cleaning quartz crystals.
    • Make sure to wear rubber gloves and not fabric gloves. The acidic residue could remain on the fabric gloves or seep through to your skin.
  3. 3
    Dispose of the acid waste properly. Since oxalic acid waste is considered a hazardous material, you need to neutralize it first before you can dispose of it. At the end of the cleaning process, the oxalic acid will be in a liquid form. You need to add garden lime (CaO) to the liquid until there is no longer any visible reaction.[7]
    • You can do this outside on the ground and wash away the remnants with a hose. Or you can do it by using a funnel to pour the spent oxalic acid into a gallon jug and add the lime in there. Then simply throw away the jug and its contents in a trashcan or dumpster.
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Expert Q&A
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  • Question
    What do you use to clean quartz crystals?
    Edward Lewand
    Edward Lewand
    Graduate Gemologist & Accredited Appraiser
    Edward Lewand is a Graduate Gemologist & Accredited Appraiser with over 36 years of experience in the jewelry industry. He completed his residency in graduate gemology at the G.I.A. in 1979, New York and now specializes in Fine, Antique and Estate Jewelry, consultations and expert witness work. He is a Certified Appraiser of the Appraiser Association of America (AAA) and an Accredited Senior Appraiser (ASA) of the American Society of Appraisers In Gems and Jewelry.
    Edward Lewand
    Graduate Gemologist & Accredited Appraiser
    Expert Answer

    Support wikiHow by unlocking this expert answer.

    I'd recommend a dash of mild dish soap and a soft rag. You don't need to use a lot of abrasive cleaners to clean quartz.
  • Question
    Can I use toothpaste to clean quartz?
    Edward Lewand
    Edward Lewand
    Graduate Gemologist & Accredited Appraiser
    Edward Lewand is a Graduate Gemologist & Accredited Appraiser with over 36 years of experience in the jewelry industry. He completed his residency in graduate gemology at the G.I.A. in 1979, New York and now specializes in Fine, Antique and Estate Jewelry, consultations and expert witness work. He is a Certified Appraiser of the Appraiser Association of America (AAA) and an Accredited Senior Appraiser (ASA) of the American Society of Appraisers In Gems and Jewelry.
    Edward Lewand
    Graduate Gemologist & Accredited Appraiser
    Expert Answer

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    I wouldn't recommend it. You don't need to use anything that strong on jewelry in general. You can use a toothbrush, for sure. I wouldn't use the toothpaste, though.
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About This Article

Edward Lewand
Co-authored by:
Graduate Gemologist & Accredited Appraiser
This article was co-authored by Edward Lewand. Edward Lewand is a Graduate Gemologist & Accredited Appraiser with over 36 years of experience in the jewelry industry. He completed his residency in graduate gemology at the G.I.A. in 1979, New York and now specializes in Fine, Antique and Estate Jewelry, consultations and expert witness work. He is a Certified Appraiser of the Appraiser Association of America (AAA) and an Accredited Senior Appraiser (ASA) of the American Society of Appraisers In Gems and Jewelry. This article has been viewed 191,756 times.
19 votes - 100%
Co-authors: 4
Updated: July 22, 2021
Views: 191,756
Article SummaryX

To clean a minor tarnish or stain off your quartz crystal, use an old toothbrush dipped in water. When you’re done removing the stains, dry the crystal in indirect sunlight. If you need to remove iron stains from your crystal, use a high-pressure water gun. Alternatively, soak your crystal in a weak solution of oxalic acid overnight, then rinse it with water the next day. For algae deposits, soak your crystal in a bowl filled with water-diluted bleach for several days. To learn how to stay safe when cleaning your crystal, keep reading!

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