Brass Astrology Necklace. Astrology has been used as powerful divination tool for political and personal events stretching back thousands of years. Babylonian astrologers, and later the Greeks, originally determined the zodiac signs by the constellation the sun was "in" on the day a person was born. The sun passes through 12 signs of the zodiac. Our eye-catching Astrology Necklace has each of the 12 zodiac signs engraved around a lightweight brass disk. At the center is a small green glass stone set inside brass mesh. The pendant is also reversible and has a majestic embossed sun. The necklace has a flat mesh brass chain that is adjustable.