Silver Crystal Power is a powerful attack that was used in the Sailor Moon S movie to destroy Princess Snow Kaguya and her Snow Dancers. In the attack all of the Solar System Senshi (Sailor Saturn excluded) combined their powers and abilities to perform this attack. Super Sailor Moon also used the excess power of the Silver Crystal to temporarily transform Luna into a human to save Kakeru. Sailor Moon stood in one spot, and all of the other Soldiers i encompassed her at the same time holding hands. Sailor Moon then summoned the Silver Crystal and held it high in the air. All of the Senshi then closed their eyes and simultaneously called out the command, "Silver Crystal Power!". Their uniforms started to glow a white/silver colour, then Sailor Moon rose into the air and a pyramid-shaped shield of light, with each Senshi at a vertex, appeared. Sailor Moon then channeled the resulting energy release through the Silver Crystal into one intense surge and sent it toward the enemies.
Because Artemis remembered the attack being used on Kaguya before, maybe Queen Serenity was the one who used it long ago.