They preserve the entire fossil remain rather than there traces.
Explanation:
Amber is a fossilized resin from an ancient forest. It used as a healing agent in folklore. It is a product of high pressure and temperature.
They occur in a wide range of color and many geological records are found in amber hidden fossils. Its main property is to preserve the complete chemical and physical properties of the fossil.
Oldest known amber was of an arthropod, often found in association with insects. The amber fossils are believed to have been derived from older Eocene deposits. Later formations of glacial drift.
While a mold of fossil is formed by an animal, plane or other organisms which upon dying to get covered sediments and later its bones are decay due to chemical processes. Mold fossils tell traces of extinct organisms like trail track etc.
Molds and casts are three-dimensional representations of organisms.
I believe that the discovery of new artifacts can bring many improvements to historical interpretations along with additional information for understanding historical facts. Thus, new causes can be found and analyzed that could lead to a certain phenomenon.