The unity sand ceremony emerged in the late 1980s as an alternative to the unity candle ceremony. The latter was a popular tradition in the Catholic faith in which a couple would light two candles individually and then light a central candle together. “As people started moving their ceremonies and celebrations out of doors, they needed to find an alternative ritual,” says life-cycle celebrant and nondenominational minister Alisa Tongg. “The flame was going out from the wind.” People started using sand as a substitute for candles.

They also like that the new practice created a keepsake from their big day.

Some couples use sand they collected while on a beach together. Others with children choose to have their families help out with the process. Couples can also choose whatever vessels they want to use, and many of those can be family heirlooms, sand hourglass timer or other meaningful objects. The ceremony is an easy way to visualize the joining together of two people into one. “The action of pouring their individual container into a large empty hourglass, making something new, and a permanent transformation is something that children of all ages understand,” says Tongg.