We have reached the top floor of the Miramostri hotel, the fifteenth. On this floor are the final six gems to collect. To find all the gems of the Master Suites use our Gem location guide on Floor 15.
Before proceeding take a look at the other published guides:
Luigi's Mansion 3 - Guide: where to find all the gems of floors B2 and B1
Luigi's Mansion 3 - Guide: where to find all the gems of floors 1 and 2
Luigi's Mansion 3 - Guide: where to find all the gems of floors 3 and 4
Luigi's Mansion 3 - Guide: where to find all the gems of floors 5 and 6
Luigi's Mansion 3 - Guide: where to find all the gems of floors 7 and 8
Luigi's Mansion 3 - Guide: where to find all the gems of floors 9 and 10
Luigi's Mansion 3 - Guide: where to find all the gems of floors 11 and 12
Luigi's Mansion 3 - Guide: where to find all the gems of floors 13 and 14
Location gems floor 15
Location of the green gem: hidden toilet in the living room
In the lowered sofa area there are two circles on the left and right sides. Place Luigi and Goommiluigi on either side to make a piece of furniture appear in the center of the floor. The green gem will come out of the locker.
Location of the purple gem: elevator in the lounge
To the left of the screen is a pipe on the wall. Send Goommiluigi through the tube to get him to the top of the elevator. Go down through the elevator hole to reach the purple gem.
White Gem location: Puzzle statue in the corridor
In the corridor head to the left side of the room and you will see a statue / portrait of Boo. Use the vacuum cleaner to turn the statue so that the shadow matches the silhouette of the ghost. This will reveal another portrait, this time of Luigi. Rotate the statue again to match the portrait. This will reveal the white gem.
Location of the red gem: book back in the library
Head to the Library and go downstairs. Turn left towards the fuse box to reach a hidden room. Inside this room is a book that you can aspire to. Take the book and place it on the shelf to the right of the key box. This will reveal a secret toilet with the red gem inside.
Blue Gem location: crawl under the main bathroom
Go through the main bathroom until you reach the shower. Close the shower if it's active, then send Goommiluigi down the drain. You will see the blue gem on a wooden bridge.
Location of the yellow gem: cell in the master bedroom
Inside the master bedroom, operate the dummy so that the floor flips over (dummy bottom right). Step on the scales and use Luigi and Goommiluigi to reach the top of the room. Here you will see the yellow gem in a cell. Go through the bars with Goommiluigi to get the gem.
Collecting all six gems listed above will unlock the Collect All Gems of the Master Suites achievement.