And most acid isn't pink.
Metals usually react with acids (copper, for example, doesn't), but most rock, being composed of silicates and metal compounds (not native metals) would be fine. Only carbonates, oxides and hydroxides would react, and often, the produced compounds would shield the rest of the rock from the acid, slowing the reaction. Hence, an acid planet would not need to be composed of glass.
An acid planet (Venus for one is an example: it rains sulfuric acid there) is perfectly stable - most compounds can survive acid. It's just the common misconception about acid acid "melting everything it touches" that leads to the belief that things that regularly come in contact with acid must be made of special materials.
not enough shadow on the left