Why does the swimming pool turn my ring black?

Chlorine, a chemical commonly used to disinfect swimming pools, can react with certain metals, including copper, silver, and gold, causing them to tarnish or turn black. Here's why:

Chlorine's Effect on Metals: Chlorine, in its chemical form (Cl2), is a highly reactive element. When dissolved in water, it forms hypochlorous acid (HOCl), which is the primary disinfectant in swimming pools. This acid can react with the surface of metals, particularly those that are prone to oxidation, such as copper, silver, and gold.

Copper: Copper is one of the metals that readily react with chlorine. When copper jewelry or accessories come into contact with chlorinated water, the chlorine in the water oxidizes the copper, forming copper oxide. This copper oxide appears as a black or dark brown layer on the jewelry's surface, giving it a tarnished appearance.

Silver: Silver is another metal that can be affected by chlorine. Similar to copper, chlorine can oxidize silver, forming silver sulfide. Silver sulfide also appears as a dark or black layer on the jewelry's surface, tarnishing its original shine.

Gold: While gold is generally less reactive compared to copper and silver, it can still be affected by chlorine over time. Prolonged exposure to chlorinated water can cause gold jewelry to appear dull or develop a yellowish tint. This discoloration is not as prominent as with copper or silver but can still be noticeable.

It's important to note that the rate at which your jewelry tarnishes or discolors depends on several factors, such as the type of metal, the concentration of chlorine in the swimming pool, and the duration of exposure. Some jewelry may show immediate effects, while others may take longer to exhibit visible changes.