Which of the following is NOT a term associated with fake stone products?

The term "Natural Stone" refers to stone that is quarried from the earth, and it has not been altered or processed to mimic the appearance of stone. This classification encompasses materials like granite, marble, limestone, and slate, which are prized for their durability and natural beauty. In contrast, the other terms, such as synthetic stone, artificial stone, and manufactured stone, are associated with products that are engineered or created to resemble natural stone, often using various materials combined to form a stone-like appearance.

Synthetic stone typically refers to engineered products made from resins and stones, while artificial and manufactured stones usually denote specific processes and materials designed to imitate the aesthetics of natural stone. Therefore, "Natural Stone" stands apart as it refers to the authentic geological material, while the other three terms revolve around man-made alternatives.