Why do these 1 kilo Silver bars come with assay cards, and what does that mean?

Understanding assaying before buying 1 kilo Silver bars can help you make more informed decisions about your investment. When buying Silver bars of this size, most investors want proof of their purity, content and weight, and that is where assaying comes in handy. To ensure each Silver bar meets the high standards set forth by Valcambi, the Silver bullion is tested and measured by an independent certified Precious Metals assayer in compliance with the Swiss Precious Metals Control Law. Once approved, each Silver bar for sale is stamped with the weight, content, purity and a unique serial number, and is packaged with an assay card listing the same information, as well as the name of the assayer.