How do milk stains and other discolourations on silver occur?

Silver can develop various discolorations and stains over time, including the common milk stains. At The Silver Mountain, we understand that these stains on silver coins, jewelry, and bars can be a nuisance, as they affect the appearance and value of the silver. We will explain what milk stains are, why they occur, and how to recognize, prevent, and remove other discolorations on silver.

What are milk stains on silver?

Milk stains are dull white discolorations that often appear on silver coins and bars. They resemble dried milk and can be difficult to remove, posing a challenge for collectors and investors alike. These stains can reduce the aesthetic value of the item in some cases.
Milk stains are sometimes caused during the manufacturing process and are the result of chemical reactions that occur when silver comes into contact with certain substances.

Causes of milk stains on silver

There are several factors that can contribute to the formation of milk spots on silver:
Manufacturing Process: Milk stains often occur during the minting of coins or the casting of silver bars. These processes use chemicals to clean or polish the silver, and if not removed properly, they can cause discoloration over time.
Influence of chemicals: During the production of silver coins, bars or jewelry, various chemicals are used. Residues of these, which remain on the silver during production or storage, sometimes react with the air and humidity, resulting in milk stains.
Storage conditions: High humidity and temperature fluctuations in the storage area accelerate the development of milk spots. This occurs especially when the silver is not properly sealed or when it is not stored in protective containers.

Other types of discoloration on silver

In addition to milk stains, other types of discoloration sometimes occur on silver. These are often the result of oxidation. Silver sometimes reacts with substances such as sulfur in the air, causing corrosion. Some common discolorations are:
Tarnish, also called patina: This is a dark layer that attaches itself to the silver by oxidation. Patina is especially undesirable for silver investment coins and bars.
Rust stains: These sometimes occur on silver objects that are not completely pure and contain small amounts of other metals. These other metals can rust when in contact with moisture.
Yellow Stains: Yellow discoloration sometimes occurs due to contact with certain chemicals or prolonged exposure to light.

How can you prevent milk stains?

Although milk stains can sometimes be difficult to avoid, taking the right precautions will reduce the chance of stains:
Store silver in a dry place: Use airtight, moisture-free storage containers to limit contact with air and moisture.
Use protective holders: Special protective holders and capsules protect the silver from harmful external influences.
Avoid skin contact: The oils and acids on your skin will cause stains and discoloration. Wear gloves when handling silver, especially coins and bars.

Maintenance and cleaning of silver

Regular maintenance can help keep silver clean and stain-free. For milk stains and tarnish, consider the following cleaning methods:
Silver polish: Use a soft silver polish for superficial tarnish. Be careful not to use aggressive cleaning agents, as these can cause scratches.
Ammonia-free cleaning products: Do not use products containing ammonia, as these will damage the protective layer of the silver.
Ultrasonic cleaning: Use a special device. Some silver items are cleaned with an ultrasonic device, which uses gentle vibrations to remove dirt and tarnish.
With these tips you can prevent milk stains and other discolorations on silver. This way you keep your silver collection in optimal condition. For more information about the maintenance and care of silver, visit our knowledge center or contact us with specific questions.