Organic materials include those made from animal products, such as leather, fur, horn, feathers, ivory, or wool, and those made from plant products, including wood, paper, and fibers. These materials are more susceptible to environmental damage than their inorganic counterparts. Colorants and coatings can also be organic materials. Synthetic materials, such as plastics, are also typically organic. Plastics have been produced for more than 100 years and are increasingly popular with collectors.
Some synthetic materials tend to be unstable and deteriorate quickly.
Inorganic materials may be easily broken, scratched, cracked, and worn by exposure to harsh weather. You may notice building facades or garden sculpture worn away by acid rain or stained by the growth of moss or lichens. White crystals of salts may grow on porous ceramics and stone, disrupting their surfaces. Metals may corrode in contact with acidic materials and excessive moisture. You may also see green corrosion on brass or silver objects, tarnish on silver, fingerprints, or marks from packing materials etched into metal surfaces.