Carbon Dioxide Snow cleaning was performed on several ceramics including sapphire and alumina plates. The surfaces were examined before and after with optical microscopy and x-ray photoelectron spectroscopy. The ceramic samples were taken from a supply of parts kept for ultra high vacuum usage. The surface composition table below shows that initially the alumina and sapphire parts had a hydrocarbon content of 49% and 38 atomic %, respectively. After cleaning, the hydrocarbon contents were lowered to 24% for the alumina sample and 17% for the sapphire sample. These reductions in surface hydrocarbons were on the order of 50%. Surface compositions values are listed below.