This St. Christopher Medallion is 28 mm with a gold filigree border and a bright white gold (Platinum) plate with scalloped edges and a bright gold St. Christopher and baby in the center. The pendant and chain together weigh 8 grams or .27 oz., more than a quarter of an ounce, which is selling today at $1,226. Absolutely perfect condition, not one scratch, the brightest gold because it is 18 K bright gold and white gold, or Platinum. The 24 inch long Serpentine chain is marked with a "750", next to the round clasp. The medallion is marked "750" on the oval bail. That means they are 75% gold/out of a possible 24K, with 9.5% fine silver and 15% copper. White 18K gold is 75% gold and 25% Platinum) 14K gold/24 is 58% gold, 12.5% fine silver and 29% copper. 12k Gold is 50% Gold and other alloys, 16% fine silver and 34% copper. I have seen plain 14K gold St. Christopher pendants selling for over $800 on R.L.