Final answer:
Artwork constructed from three-dimensional materials, including found objects, is identified as assemblage. This technique involves the combination of various objects to create new forms, with notable examples like Duchamp's Readymades and Rauschenberg's Combines. While mosaic and collage are related art forms, they are distinct from assemblage.
Step-by-step explanation:
Artwork constructed from three-dimensional materials, including found objects, is known as assemblage. This artistic process involves the utilization of found, manufactured, or altered objects that are welded, glued, bolted, or wired together to create a new and unique form. Assemblage has historical predecessors such as Duchamp's Readymades and Rauschenberg's Combines from the 1950s. Contemporary artists like Jessica Stockholder incorporate not only form but theory into their assemblage works.
On the other hand, mosaic is a technique in which an image is created using small pieces (tesserae) of hard material like stone, glass, and metal. The ancient Romans and Greeks, as well as Renaissance artists, famously used mosaics to decorate floors and walls, crafting these long-lasting artworks by embedding the tesserae in a substrate and then sealing it with grout.
Collage involves the assembly of various materials such as newspapers, magazines, photographs, and found objects, glued down to a surface. Dadaists, following the invention of paper in China around 300 BCE, used collage to create compositions, often as commentary on society or art.
Impasto is a painting technique where paint is laid on a surface in very thick layers, typically oil paint, that makes the brush or palette knife strokes visible. It is not relevant to the question regarding three-dimensional artworks including found objects.