Researchers at the Royal Canadian Mint recently developed a proprietary method for reducing the occurrence of white spots on silver bullion coins with what the Crown corporation is calling “MintShield” surface protection.
All 2018 Silver Maple Leaf (SML) bullion coins incorporate this new technology, which—in addition to current features such as “Bullion Data” anti-counterfeiting technology, laser micro engraving and 99.99 per cent purity—adds another layer of security to one of the world’s most popular silver bullion coins.
“The Mint has a long history of revolutionizing the bullion industry with advances in purity and security, and MintShield is yet another exciting step in that direction,” said Sandra Hanington, Mint president and CEO. “By protecting the dazzling appearance of our Silver Maple Leaf bullion coins, our engineers have found a new way to bolster the world-wide appeal of our signature silver bullion product.”
White spots—often called “milk spots”—are surface discolorations which sometimes mar the appearance of silver bullion products. Unlike tarnishing, which is a by-product of oxidation, white spots don’t have a single, predictable cause and this has complicated the search for an effective solution to a problem affecting silver bullion coin producers all over the world. By reducing and delaying the onset of white spots on SML bullion coins with MintShield surface protection, the Mint has finally turned the tables on this challenging issue.
According to the Crown corporation, MintShield is “invisible to the eye” and “doesn’t alter a coin’s composition or purity and can be applied efficiently in a large-scale production environment. Laboratory testing, which simulates long-term use, has demonstrated Silver Maple Leaf bullion coins treated with MintShield successfully resist white spotting compared to all other silver bullion products in the market.”