Well before the lead pencil was invented and mass produced some artists during the Renaissance period used a silver wire to mark a paper surface so prepared to be slightly abrasive and thus able to hold the silver particles well. Once the silver was exposed to the air it would soon oxidize and darken, giving a pencil drawing like effect. 

These types of drawings are called silver points. Silver was not the only medium used, see: Metalpoint Drawings.

Silverpoints have an interesting quality, where the color of the silver is gray when it is first applied to the surface, after exposure to air it tarnishes and becomes warm, mellow, brown in its tone. 

Silver wasn't always used by everyone, chalk was actually more popular because it took less preparation and was cheaper, but silver point was still one of the main drawing materials in the Renaissance, often used by artists preferring detail & precision in their drawing. 

Silverpoint drawings can still be done today. Take a clutch pencil and instead of ordinary lead insert a short length of silver wire of the appropriate thickness, and obtained from a jewelry supply store. Draw on one of the pastel papers that has a finely abrasive surface, these are available in paper supply stores. Don’t be surprised if the line is ‘softer’ than pencil lines you are used to, as this is part of the charm of the medium.