Definition:
Bridge jewelry is made of precious metal - usually sterling silver. Gemstones used in bridge jewelry are semi-precious. That would include any gemstone that is not ruby, emerald, diamond or sapphire.
Examples of semi-precious gemstones are aquamarine, opal, garnet, citrine, topaz, amethyst - the list goes on and on. Just a word here on the quality of gemstones. A poorly cut, bad specimen of ruby can be worth much less than a excellent specimen of say, aquamarine or turquoise.
