The Salt Lake Temple Moon Stones
The Moon Stones on the Salt Lake Temple are located midway up each of the pilasters and on the towers; and are set vertically between the earth stones and the sun stones. Each moon stone is carved to depict the four phases of the moon: Full, Quarter, Half and New Moon. The solid granite blocks that make up the walls of the Salt Lake Temple was difficult to carve much detail in, so the stone cutters etched out the phases as best they could with the tools they had. Starting from the East center tower and going from right to left, the moon stones are deliberately arranged to represent a full twelve month moon cycle spanning from April to April. The moon stones have several symbolic meanings that pertain to Biblical worship practices as well as LDS Church beliefs.
In the Old Testament, the House of Israel used the phases of the moon as an indicator for religious observance and worship, including festivals, sacrifices, offerings and temple attendance (Ezekiel 46). So the moon stones are a sign to remind faithful Latter-day Saints to attend the temple regularly.
The Bible and the Book of Mormon teach that the believers and the faithful are supposed to watch the heavens for signs of the Second Coming of Jesus Christ. According to the Bible, the moon plays a prominent role in some of these signs (Acts 2:20, Matthew 24:29), so the moon stones act as a reminder to keep watch and prepare for the return of The Savior.
In LDS theology the moon is the symbol of the Terrestrial Kingdom, which is the second kingdom in the Three Degrees of Glory. This is typified on the temple with the placement of the moon stones in between the Earth Stones, which represents the Telestial Kingdom, and the Sun Stones, which represents the Celestial Kingdom.
The sequence of the twelve month moon phases begin on the center tower of the east face of the temple. The sequence begins and ends in April. The month of April is significant because the crucifixion and resurrection of Jesus occurred in April and, according to LDS belief, Jesus was also born in April, on the 6th. The East tower represents the Melchizedek Priesthood, so the sequence symbolizes that everything begins and ends with Jesus and His priesthood. The month of April has additional significance to Latter-day Saints because the church was officially established on April 6, 1830.
Depicting the four phases of the moon is also a symbolic expression of the stages of human progression in the gospel; namely birth, life, death and resurrection. The New Moon and the Full Moon is also a symbol of our spiritual journey from darkness to light, from error to truth, and from unbelief to faith.