Some embodiments include an apparatus having a polishing mechanism configured to polish a surface of a wafer. The polishing mechanism converts fresh slurry to used slurry during a polishing process. At least one emitter is configured to direct electromagnetic radiation onto or through the used slurry. At least one detector is configured to detect transmittance of the electromagnetic radiation through the used slurry or reflection of the electromagnetic radiation from the used slurry. An identification system is coupled with the at least one detector and is configured to identify a property of the used slurry indicating that an endpoint of the polishing process has been reached. Control circuitry is coupled with the identification system and is configured to stop the polishing process based on receiving a trigger from the identification system. Some embodiments include polishing methods.