Have you ever seen the Silver Mirror trick at a chemistry show? That’s when silver is precipitated out of solution onto a glass surface. The demo consists of a series of clear solutions being combined in a glass flask. As the presenter swirls the flask, a shiny mirror forms on the inner surface of the glass. The reaction utilizes Tollens’ reagent, which is used to determine the difference between aldehydes and ketones. I thought it might be cool to modify the procedure slightly to be able to grow silver crystals. This turned out to be slightly more challenging than I predicted, mostly because the Tollen’s reagent is designed to form a smooth silver film on any glass surface, so crystals are not the first structures produced. However, with some tweaking and dilution, I was able to get a slide with some individual crystals. Above is a picture through the Foldscope and below is a macro photo of the prepared slide.