Rhodochrosite and rhodonite: similar names, similar color, different minerals

Rhodochrosite and rhodonite get confused constantly because of how similar their names and colors are, but they are chemically distinct. Rhodochrosite is a manganese carbonate, typically pink to red with banding, and it will react with dilute acid the way other carbonates do, a quick way to separate it from its look alike. Rhodonite is a manganese silicate, generally pink to reddish brown with characteristic black manganese oxide veining running through it, and it will not react to acid at all. If you remember only one distinguishing test, the acid reaction is the fast, reliable one.