Argentium sterling silver, often marked A925, is a silver alloy composed of smelting 92.5% silver, 7.5% copper, and a pinch of germanium.
The "A925" mark on a ring indicates that it is made of sterling silver (92.5% silver content) and the "A" may denote the manufacturer or a specific design line. The value of a ring marked A925 depends on various factors, including its design, craftsmanship, and any gemstones it may contain. Generally, sterling silver rings can range from $20 to several hundred dollars, depending on these factors. For an accurate appraisal, it’s best to consult a jeweler or appraiser.