Abstract: An apparatus and method for the cryogenic purification of gaseous mixtures is provided. The apparatus comprises a heat-insulated hermetically sealed vessel which contains liquid hydrogen. Immersed within the liquid hydrogen are a number of serially connected cartridges which contain chips of a thermally conductive mixture. A mixture of neon and helium is input into the apparatus. The neon freezes, while the helium passes through the apparatus in a gaseous state. The resulting neon is allowed to thaw into a liquid or gaseous form and is highly pure.