MODERN Period 1940 The flamboyant curves and bows of modern period often in large pieces of jewelry make this a very obvious period. Yellow, pink and even green gold were used at this time to in a statement of freedom of expression in modern period. Copper was used widely during the war in the making of gold as nikel was in short supply, used primarily in the in the making of arms during modern period. A popular stone of modern period was calibre-cut ruby or even synthetic ruby, often channel-set in an expression of curvature and color. This styleof modern period is presently highly collectible and can still be purchased very reasonably.