A system and method for separating Kr gas from Xe gas utilizing natural clinoptilolite. The method includes separating Kr gas from Xe gas by selectively adsorbing Kr gas. The method includes providing a vessel comprising a Kr adsorbent bed comprising a natural clinoptilolite adsorbent. A feed gas comprising Kr gas and Xe gas is exposed to the Kr adsorbent bed for a residence time to selectively adsorb sufficient Kr gas from the feed gas to form a Xe enriched gas raffinate product. The Xe enriched gas raffinate product is removed from the vessel. Thereafter, the Kr adsorbent bed is regenerated to release a Kr enriched gas extract product.