A gold mangalsutra is a gold necklace used on a wedding day in a Hindu ceremony. The ceremony, known as "Mangalya dharanam" (wearing the auspicious), involves the groom tying the mangalsutra around his wife's neck, bestowing upon her the status of life mate and wife.
As long as the couple remains married, the wife continues to wear the mangalsutra as a symbol of their mutual love, marriage and goodwill. It symbolizes their mutual understanding and commitment to each other.
On the day of the wedding, turmeric paste is used to prepare a yellow thread, which is tied around the neck of the bride using three knots, while the priest issues prayers and recites Vedic hymns. The exact ordering of the knot tying varies, although some traditions feature the groom tying the first knot and his sisters tying the second and third. Later, this can be replaced with a gold chain featuring an elaborate pendant, and this would be a gold mangalsutra.
In modern times, wearing a mangalsutra has become more of a fashion decision than an actual symbol of the institution of marriage. Most career women will not wear a mangalsutra with a business suit. While the gold mangalsutras in the past have been elaborate and heavy, they have become more sleek and slender in recent years.