"Silver Moon Crystal Power" is a light-based/energy-based attack used by Sailor Moon in the anime and Neo-Queen Serenity in the manga.
Manga[]
In the manga, it is said that Neo-Queen Serenity used this attack to awaken the Amazoness Quartet and turn them back into the Sailor Quartet. She did not call out any attack name or phrase when she performed it though.
Anime[]
This was Sailor Moon's final attack in the anime. She attempted to use this to turn Sailor Galaxia back to normal, but it was unsuccessful.