Took a bit of sleuthing but our suspicions were correct. We thought this knife might be sterling when we found it but it was unmarked. Fortunately it?s a pretty well known pattern by Hotchkiss Schreuder and even though their initials were mostly faded, we were able to use what was left to compare the pattern (Medallion). As H S only worked with sterling and coin silver, we were relieved to find our gut instinct was alive and well. We are erring on the side of caution and promoting this as coin silver as most of their sterling was marked on the blade. The coin silver was not. If you have this pattern, there is no difference in the pattern between coin silver (.900) and sterling(.925). They are interchangeable. This particular knife was sold through DC Jaccard Co in St Louis MO. which operated from 1864-1873 Founded by D. Constant Jaccard. Became Mermod, Jaccard Co. in 1873. So we know this particular knife was made between 1867 (when the Medallion pattern was introduced and 1876 (when it became Mermod, Jaccard Co). This master butter knife is in wonderful shape and is not monogrammed or personalized in any way. It weighs a whopping 43 grams. See photos. Will ship USPS with tracking to winning buyer