Nine two five. The three numbers attached to a specific alloy: sterling silver. 92.5% fine silver, and 7.5% copper and other alloys. I love the versatility of sterling: it is forgiving to cast and willing to work-harden under a planishing hammer. I've had many porous castings, and a few cracked vessels. Solder helps, and can be alloyed to match. The structure of metal is fascinating and mysterious - I am always in awe. I've been working on a publication on the "how-to" of cuttlefish bone casting. It is important to understand the makeup of alloys before you melt them down, otherwise you might be caught by surprise.