There are six collectible gems on each floor in Luigi’s Mansion 3. In this guide, I’ll show you where to find all six gems on the 11F floor and tell you how to get your hands on them. You’ll need to unlock certain abilities before you’ll be able to collect some of these gems, so you may have to come back later on in the game.
Please note that some of the gems will appear clear rather than coloured in the screenshots seen below, this is because I had already collected them during my playthrough before creating this guide.
Gem #1 – Bladed Bedroom
When you get into the Bladed Bedroom you’ll spot a circular board on the back wall, which looks suspiciously like the kind of board that somebody gets tied to during knife-throwing acts at the circus. Stand to the side of it and use your vacuum on it to make it spin, and a bunch of ghostly knives will appear and fly into it. Wait until they disappear and then use your vacuum on it again and the knives will appear again, this time flying into the board in a square formation and throwing out the Red Gem.
Gem #2 – Suit Bathroom
Head into the Suit Bathroom and vacuum up all of the playing cards which are scattered around the room to make each suit light up above you. Once all of them light up, the light itself will open up and drop out the Clear Gem.
Gem #3 – Lounge
Make your way to the Lounge and perform a Suction Shot on the panel next to the door in the top right corner of the room to reveal a green light underneath. Now, summon Gooigi and stand him in front of the glass cabinets in the bottom left corner of the room. Switch back to Luigi and use your Strobulb on the green light to temporarily open all of the glass cabinets, then quickly switch back to Gooigi and use his vacuum on the now-open cabinets to retrieve the Green Gem.
Gem #4 – Trainer’s Bedroom
Go into the Trainer’s Bedroom and you’ll find a piggy bank next to a fallen chair in the bottom left corner of the room. Use your vacuum to suck up the piggy bank and fire it into the wall to get hold of the Blue Gem.
Gem #5 – Mirror Bathroom
In the Mirror Bathroom, look in the mirror in the top right corner of the room and you’ll see the reflection of a picture in the opposite corner. Shine your Dark Light on this corner (bottom left) and the Yellow Gem will appear.
Gem #6 – Hall
Walk into the Hall and a huge hat will fall on top of your head. Keep it on (don’t worry if you’ve already knocked it off, just stand next to it and press X and you’ll put it back on) and walk over to the right hand side of the room. Stand in front of the statue of three ghosts, two of which are also wearing a hat, and then perform a Burst (ZL + ZR) to send the hat flying on to the third statue. This will cause a spiral staircase to appear which will lead you to a chest which contains the Purple Gem.
And that’s it! Congratulations, you collected all six gems.