A fine polishing powder for use with any polishing tool; this is mainly for use with polishing pads/machines but is possible to achieve some effects using a cloth and applying by hand.
Just mix a small amount of powder and water to make a milk-like mixture. Then apply thinly to the polishing disk before turning on. If preferred, you could use a spray bottle to apply the mixture to the pad.
TIP: When using with a polishing pad: Mix the cerium oxide up quite watery and use a squeezy bottle. If it's a new pad, make up a thinnish paste and work it into the felt pad all over to get it started. Have the machine running quite slowly and use a very slow water drip into the centre of the pad otherwise you'll just wash it all down the drain. It's very quick to polish. A word of caution if you are polishing something circular like a little drop vessel, be careful it doesn't suction itself onto the pad and take you by surprise and you let go of it. Our teacher Becky Wills suggests making a gaffer tape handle for things so if your hands get wet you can still hang onto it.