The readers of the first two editions of Stone: Properties, Durabi- lity in Man's Environment, were mostly architects, restoration architects of buildings and monuments in natural stone, profes- sionals who sought basic technical information for non-geologists. The increasing awareness of rapidly decaying monuments and their rescue from loss to future generations have urged this writer to update the 1973 and 1975 editions, now unavailable and out of print. Due to the 20-year-Iong interval, extensive updating was necessary to produce this new book. The present edition concentrates on the natural material stone, as building stone, dimension stone, architectural stone, and decorative field stones. Recently, the use of stone for thin curtain walls on buildings has become fashionable. The thin slabs exposed to anew, unknown complexity of stresses, resulting in bowing of crystalline marble, has attracted much negative pUblicity. The costs of replacing white slabs of marble on entire buildings with its legal implications have led construction com- panies into bankruptcy. We blame many environmental problems on acid rain. Does acid rain really accelerate stone decay that much? Stone preservation is being attempted with an ever-increasing number of chemicals applied by as many specialists to save crumbling stone. Chemists filled this need during a time of temporary job scarcity, while the general geologist missed this opportunity; he was too deeply involved in the search for fossil fuels and metals.