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 Gold is a coating of metal whose color looks like 14k-18k gold, making jewelry more affordable but at the same time keeping the good quality. Imitation gold has a tint of red, and appears to have a reddish yellow hue.