It was very true because of the magnificent designs that came out of this period. This era was centered around women and the beauty of nature, and the pieces were often voluminous. Enamel was a commonly used material in Art Nouveau jewelry, as the period was more focused on the importance of design than on the materials used to create it. The Art Nouveau period occurred before the start of World War I, when mass production took over the production of many products, including some jewelry. Amethysts are a semi-precious variety of quartz that are valued for their differences.