Amethyst is a type of quartz that is mostly found in geodes and hollow agates. It is composed of silicon dioxide, and scores a 7 on the Mohs hardness scale. From different angles, amethyst occurs in primary hues from a light pinkish violet to a deep purple.
Imitation Rhodium uses a similar-looking material to substitute for rhodium. It makes the jewelry more affordable, but at the same time keeps the same appearance and quality as a rhodium coating.