PRECIOUS STONES

The term “precious stones,” now abolished in certain legislations but still commonly used, traditionally referred to four gems: the Emerald, the Diamond, the Ruby / Jewel and the Sapphire. Other gems were classified as “fine stones” (or semi-precious stones). This distinction, considered arbitrary from a gemological standpoint, has been replaced in several countries by the sole categories of diamond and colored stones. In watchmaking and jewelry, these gems are used for decorative purposes: Setting (stone/jewel setting) of eyeglasses, dials, cases and bracelets, where they enhance the brilliance and value of a piece. Ruby / Jewel and Sapphire, colored varieties of corundum, also have historical technical importance: Ruby / Jewel, once natural then synthetic, is used in the manufacture of watch jewels that reduce friction. The selection, cutting and Setting (stone/jewel setting) of precious stones fall within highly specialized art crafts.