Moonstone (noun)

1. A type of feldspar with a pearly or opalescent luster, often white or gray in color.
2. A gemstone cut from this type of feldspar.
3. Something that resembles a moonstone in appearance or quality.

Origin:

Moonstone is so named because of its milky, pearly luster, which is thought to resemble the light of the moon. the word has been in use since the 16th century.

Examples:

1. The moonstone was used in the engagement ring to symbolize the couple's love, which was as constant as the moon.
2. The moonstone pendant cast a soft, ethereal light as the woman walked down the aisle.
3. The cake was decorated with sugar moonstones, which shimmered in the candlelight.
4. The artist was inspired by the soft, pearly light of the moonstone to create a series of paintings.
5. The lake was still and glassy, reflecting the full moon like a giant moonstone.