Additionally, gold is extremely unreactive, hence it does not tarnish or corrode over time. A gilt surface also does not tarnish as silver does. Unfinished brass will eventually tarnish and thus must be periodically polished to maintain its appearance. It also rejects any substance that would damage or tarnish it. However, it quickly oxidizes and absorbs atmospheric sulfur to create a dark, low-reflectivity tarnish. Pure copper is orange-red and acquires a reddish tarnish when exposed to air. Character assassination is an attempt to tarnish a person's reputation. Surely the heroes of Egmont will not tarnish their record! It may also tarnish and turn a greenish color. Otherwise, substandard equipment with overrated nameplate capacity may tarnish the industry. She scolds anyone who would attempt to tarnish Alice's innocence to any degree. Metallic Rb reacts with O, as indicated by its tendency to rapidly tarnish in air. This inhibits further reaction, although the appearance of a film of "tarnish" is quite evident. Such samples slowly tarnish, becoming grey and finally black at the surface. Some tarnish around the edges is normal.