Where to find every gem in Luigi's Mansion 3

Luigi finds the yellow gem in Paranormal Productions
Luigi finds the yellow gem in Paranormal Productions (Image credit: iMore)

Luigi's Mansion 3

Luigi's Mansion 3 (Image credit: iMore)

Luigi's Mansion 3 is simply stuffed with collectibles -- most of them cash. But as you vacuum up chunks of change, you'll also come across hidden gems of different colors and shapes. Each area has six gems, each one a different color, and collecting all 102 gems in the game gets you a special cosmetic upgrade for Luigi.

However, it can be tricky to find some of these hidden gems, so we've helped you out if you're stuck on any with a guide to every gem location in the game.

By the way, we've also made guides to help you find every Boo as well as help you defeat every boss in the game. Without further ado, here's the guide to find every gem in Luigi's Mansion 3.

Every gem location in Luigi's Mansion 3

We'll list all the floors from lowest to highest, and the gems in color order: clear, red, blue, green, purple, yellow.

B2 - Boilerworks

Note: You can't get all the gems in the Boilerworks on your first visit. You'll have to wait until your second visit with the water drained and Toad helping you to unlock some of the areas.

Luigi finds the clear gem in the Boilerworks

Luigi finds the clear gem in the Boilerworks (Image credit: iMore)

Clear: During the escape with Toad, you'll detour through a series of new rooms, including one with a lot of paint buckets in a corner. Suck up a paint bucket and throw it at the wall in the alcove where the buckets were found, and a gem ghost will appear for you to suck up.

Luigi finds the red gem in the Boilerworks

Luigi finds the red gem in the Boilerworks (Image credit: iMore)

Red: This one's in the storage room to the right of the "central" room with the rotating platform. Send Gooigi through the pipes, and use Luigi's vacuum on the valve behind him to turn off the water and clear a path for Gooigi to reach the gem.

Luigi finds the blue gem in the Boilerworks

Luigi finds the blue gem in the Boilerworks (Image credit: iMore)

Blue: In the small office, shine your blacklight in the center of the room at the ceiling to turn on a disco ball. Then, shine it in the bottom left corner to reveal a boiler. Finally, go to the desk and interact with the coffee pot to make too much coffee, destroying the panel and revealing the gem.

Luigi finds the green gem in the Boilerworks

Luigi finds the green gem in the Boilerworks (Image credit: iMore)

Green: When walking along the bed of the "river" once it's drained, you'll reach a turn where you see a small lift on the right. Send Luigi up while Gooigi pulls the chain to the left, then vacuum up the gem.

Luigi finds the purple gem in the Boilerworks

Luigi finds the purple gem in the Boilerworks (Image credit: iMore)

Purple: Still while walking along the waterway, you'll eventually come across a drain in the floor for Gooigi. It leads to a submarine. Once inside, suck up the torch on the left and light the fire on the right for this gem.

Luigi finds the yellow gem in the Boilerworks

Luigi finds the yellow gem in the Boilerworks (Image credit: iMore)

Yellow: This one's tricky to see but easy to get. In the very first room with the elevator, send Gooigi up the pipe near the door to the wooden platform. From there, he can walk behind the structure to the left and around, which will lead him straight to the gem.

B1 - Basement

Note: You can't get all the gems in the Basement on your first visit. You'll have to wait until you have all your tools, including Gooigi and the Blacklight, to fully explore this floor.

Luigi finds the yellow gem in the Basement

Luigi finds the yellow gem in the Basement (Image credit: iMore)

Clear: In the garage, vacuum up the tarp covering the car, then use your flashlight to open the trunk for the gem.

Luigi finds the red gem in the Basement

Luigi finds the yellow gem in the Basement (Image credit: iMore)

Red: Also in the garage, but you need Gooigi. Send him through the fence that is blocking off the breakers, then use his plunger to pull the cover off the electrical box. Finally, use the flashlight to open the gem box.

Luigi finds the yellow gem in the Basement

Luigi finds the yellow gem in the Basement (Image credit: iMore)

Blue: Still in the garage, head all the way to the right and use your plunger to remove a suspicious-looking panel from the wall. Follow the path in the elevator shaft until you come to a grate in the floor for Gooigi to slip through. Send him in to get the gem.

Luigi finds the green gem in the Basement

Luigi finds the green gem in the Basement (Image credit: iMore)

Green: This is probably the first gem you'll see in the game. It's tumbling in a dryer in the laundry room, and you can open it easily enough with your plunger.

Luigi finds the purple gem in the Basement

Luigi finds the purple gem in the Basement (Image credit: iMore)

Purple: Shine your blacklight on the portrait of a gem in the hallway.

Luigi finds the yellow gem in the Basement

Luigi finds the yellow gem in the Basement (Image credit: iMore)

Yellow: On your way up the stairs to the first floor, there's a grate in the floor at the top for Gooigi. Send him down to get the gem.

1F - Lobby

Note: 1F and 2F blend into one another a bit, but essentially 1F is the entire lobby (including the part at the top of the stairs) and 2F is through the doors at the top of the lobby (restaurant, ballroom, etc)

Luigi finds the clear gem in the Lobby

Luigi finds the clear gem in the Lobby (Image credit: iMore)

Clear: Use your blacklight under the window in the lobby near the desk on the left to reveal a missing couch and a gem ghost.

Luigi finds the red gem in the Lobby

Luigi finds the clear gem in the Lobby (Image credit: iMore)

Red: Aim your plunger at the round design on the desk beneath the painting to the left of the elevator and pull to open the desk and portrait and get the gem.

Luigi finds the blue gem in the Lobby

Luigi finds the clear gem in the Lobby (Image credit: iMore)

Blue: Head up the stairs and to the left, where you'll see a long carpet pulled up a bit on one end. Blow air at it to roll it up and reveal a grate for Gooigi. Send him in, follow the path to push the gem out above the desk, then send Luigi to go get it.

Luigi finds the green gem in the Lobby

Luigi finds the clear gem in the Lobby (Image credit: iMore)

Green: Use your plunger to break the plant next to the elevator.

Luigi finds the purple gem in the Lobby

Luigi finds the clear gem in the Lobby (Image credit: iMore)

Purple: Behind the main counter, there's a bulb you can flash your flashlight at to reveal a gem

Luigi finds the yellow gem in the Lobby

Luigi finds the clear gem in the Lobby (Image credit: iMore)

Yellow: In the main open area of the lobby, there are two colored squares in the design on the floor that are actually pressure plates (one is hidden by a destroy-able easel). Have Luigi and Gooigi stand on one each, then aim your vacuums at the chandelier and get sucking to make the gem (and a lot of money) appear.

2F - Mezzanine

Note: 1F and 2F blend into one another a bit, but essentially 1F is the entire lobby (including the part at the top of the stairs) and 2F is through the doors at the top of the lobby (restaurant, ballroom, etc)

Luigi finds the clear gem in the Mezzanine

Luigi finds the clear gem in the Mezzanine (Image credit: iMore)

Clear: Head to the rightmost restroom and open the stall doors, using your plunger to open the third. Suck up the floating newspaper (you have to get close to it like a curtain or cloth), and a gem ghost will appear.

Luigi finds the red gem in the Mezzanine

Luigi finds the red gem in the Mezzanine (Image credit: iMore)

Red: Use your vacuum on the chandelier in the center of the ballroom to reveal a storage area on your left. Head inside for the gem.

Luigi finds the blue gem in the Mezzanine

Luigi finds the blue gem in the Mezzanine (Image credit: iMore)

Blue: In the kitchen, use your plunger to open the freezer and suck an ice block up from the shelf on the left into your vacuum. Carry it back into the kitchen and hold it over the stove to melt the gem out.

Luigi finds the green gem in the Mezzanine

Luigi finds the green gem in the Mezzanine (Image credit: iMore)

Green: This one's in a safe in the dressing room that you can reveal by vacuuming up the hanging clothes and flashing your flashlight to open it.

Luigi finds the purple gem in the Mezzanine

Luigi finds the purple gem in the Mezzanine (Image credit: iMore)

Purple: In the Entertainment Room (with the billiards table) suck up the sword hanging on the wall, and then aim it at the center of the dart board in the back to get this gem.

Luigi finds the yellow gem in the Mezzanine

Luigi finds the yellow gem in the Mezzanine (Image credit: iMore)

Yellow: Just outside the dining hall, you can see two fans up on top of the wall. Have Luigi and Gooigi work together to get them both spinning at once and the gem will drop down.

3F - Hotel Shops

Luigi finds the clear gem in the Hotel Shops

Luigi finds the clear gem in the Hotel Shops (Image credit: iMore)

Clear: In the central area on the upper level, head to the right and toward the camera until you see a broken gate. Use burst to open it, and then follow the path to the end and through until you're above the elevator hall. Keep going to collect the gem at the end.

Luigi finds the red gem in the Hotel Shops

Luigi finds the red gem in the Hotel Shops (Image credit: iMore)

Red: In the Boutique, use the plunger on the mannequin on the left to open a hidden door. Inside you can suck up the gem from a rafter.

Luigi finds the blue gem in the Hotel Shops

Luigi's Mansion 3 (Image credit: iMore)

Blue: Keep using your flash on the vending machine in the hallway until it gives you the gem (it will give you rats several times first)

Luigi finds the green gem in the Hotel Shops

Luigi finds the green gem in the Hotel Shops (Image credit: iMore)

Green: Outside of the accessories shop, you can see part of a ladder hanging down. Use your blacklight to finish it, climb up, and get the gem.

Luigi finds the purple gem in the Hotel Shops

Luigi finds the purple gem in the Hotel Shops (Image credit: iMore)

Purple: In the men's restroom, you can see a grate on the floor in the mirror reflection that isn't there on your side. Use your blacklight to reveal it and send Gooigi in. At the end of the room, he can use the vacuum to turn off the water in the women's restroom above. Head back, and send Gooigi through the other pipe (you'll have to remove the lid on it first). The gem is in the farthest toilet.

Luigi finds the yellow gem in the Hotel Shops

Luigi finds the yellow gem in the Hotel Shops (Image credit: iMore)

Yellow: You can see this one in a glass cabinet, which can be broken with suction or by smashing ghosts or other objects around the room.

4F - The Great Stage

Note: You can't get all the gems in the The Great Stage on your first visit. You'll have to wait until you have all your tools, including the upgraded Poltergust, to fully explore this floor.

Luigi finds the clear gem in the Great Stage

Luigi finds the yellow gem in the Great Stage (Image credit: iMore)

Clear: Something's missing on the right-hand sink in the bathroom. Shine your blacklight to reveal it, and a gem ghost.

Luigi finds the clear gem in the Great Stage

Luigi finds the yellow gem in the Great Stage (Image credit: iMore)

Red: Head into the dressing room located behind the stage on the left and shine the blacklight on the piano, then play it.

Luigi finds the blue gem in the Great Stage

Luigi finds the yellow gem in the Great Stage (Image credit: iMore)

Blue: This one's a bit involved. Start in the restroom, and use Gooigi to get through the fence blocking the toilet and pull the chain. A ghost door will reveal itself, and Luigi can now head through. Once inside, use your vacuum on the bottles on the back wall, starting from the left and moving to the right to hit them all at once. It'll play a catchy tune and reveal the gem.

Luigi finds the green gem in the Great Stage

Luigi finds the yellow gem in the Great Stage (Image credit: iMore)

Green: On the stage, there's an area of floor that looks a bit different than the others. Use burst on it to reveal a socket for the upgraded Poltergust. Once you get the upgrade, plug in and suck up the entire back wall of the theatre, revealing a TV that will take you to the gem.

Luigi finds the purple gem in the Great Stage

Luigi finds the purple gem in the Great Stage (Image credit: iMore)

Purple: Do the most obvious thing you can with the tuba in the elevator hall: blow into the mouthpiece with the Poltergust. A gem will appear, and you can have Gooigi suck it up.

Luigi finds the yellow gem in the Great Stage

Luigi finds the yellow gem in the Great Stage (Image credit: iMore)

Yellow: Use your flash on the popcorn machine several times until the whole thing bursts and gives you a gem.

5F - RIP Suites

Note: You can't get all the gems in RIP Suites on your first visit. You'll have to wait until you have all your tools, including Gooigi and the blacklight, to fully explore this floor.

Luigi finds the clear gem in RIP Suites

Luigi finds the clear gem in RIP Suites (Image credit: iMore)

Clear: In Room 508, head out onto the back porch and look through the telescope until a ghost spooks Luigi. It's a gem ghost who you can fight for the gem.

Luigi finds the red gem in RIP Suites

Luigi finds the red gem in RIP Suites (Image credit: iMore)

Red: You'll need Gooigi for this. Team up with him to shoot plungers at the couch blocking the left-hand side of the floor and pull it out of the way. Then use Luigi's blacklight to reveal room 501. Head inside, and repeat in the top right of the room where you can see an outline where a door should be. Head through and follow the path along the righthand side to take the gem from a gargoyle.

Luigi finds the blue gem in RIP Suites

Luigi finds the blue gem in RIP Suites (Image credit: iMore)

Blue: Head into the laundry room and use your plunger to open a panel in the top left of the room.

Luigi finds the green gem in RIP Suites

Luigi finds the green gem in RIP Suites (Image credit: iMore)

Green: This one's in the bust of a monster's mouth in the hall. Suck up the heavy ball from the display to the left of it and fire it at the statue to release the gem.

Luigi finds the purple gem in RIP Suites

Luigi finds the purple gem in RIP Suites (Image credit: iMore)

Purple: This one's in room 507. Head to the bathroom and suck up the sheet on the wall to reveal a hidden room. The gem is inside, though you may have to use your plunger to clear some objects out of your path.

Luigi finds the yellow gem in RIP Suites

Luigi finds the yellow gem in RIP Suites (Image credit: iMore)

Yellow: This one's a bit involved. If you haven't already, use Gooigi and your plungers to clear the couch out of the way blocking the left-hand side of the floor. Head past the hidden door to room 501 to another hidden door, 502. Reveal it with the blacklight and head inside, then use your plunger to move the cart and enter the bathroom. Send Gooigi down the grate and have him use his plunger on the boards behind him to reveal a valve. Then have him move the valve all the way to the left with his Poltergust. Return to Luigi, suck up the shower curtain, and use the vacuum to turn the shower on. Open the suitcase that comes out for the gem.

6F - Castle MacFrights

Luigi finds the clear gem in RIP Suites

Luigi's Mansion 3 (Image credit: iMore)

Clear: You should find this one automatically after beating the boss on your way out. It's in front of a suit of armor up in the stands, just past a chest.

Luigi finds the red gem in RIP Suites

Luigi's Mansion 3 (Image credit: iMore)

Red: In the Hall of Armor, you might notice there's a missing suit on the top left. Shine your blacklight to reveal it, then use your plunger to bust it for the gem.

Luigi finds the blue gem in RIP Suites

Luigi's Mansion 3 (Image credit: iMore)

Blue: In the Cellar (the one with all the barrels), use your plunger to pull out the front of the rightmost giant barrel. Head inside to the back, then walk to the right until you can't anymore, then head up the ladder (it might be hard or impossible to see). The gem's at the top.

Luigi finds the green gem in RIP Suites

Luigi's Mansion 3 (Image credit: iMore)

Green: In the Coliseum Hallway right before the arena where you fought the boss, vacuum the tapestries off the walls until you see a weird looking indentation, almost like a door is missing. Use your blacklight to make the door appear for a gem and an achievement.

Luigi finds the purple gem in RIP Suites

Luigi's Mansion 3 (Image credit: iMore)

Purple: In the armory, you might notice some weird looking bricks at the top center. Use your plunger to remove them, revealing a hidden chest with a gem.

Luigi finds the yellow gem in RIP Suites

Luigi's Mansion 3 (Image credit: iMore)

Yellow: Head to the room with the cages, stocks, and windmills. Use Luigi to blow on a fan on the left wall (by the door) to lower the gem's cage, then send Gooigi through to get the gem.

7F - Garden Suites

Luigi finds the clear gem in the Garden Suites

Luigi finds the clear gem in the Garden Suites (Image credit: iMore)

Clear: There are several bathrooms on this, uh, "floor," but the one you want here is the one covered in ivy you can vacuum up. Use your vacuum to turn on the tub, then shine the blacklight on the floor near the sinks to reveal a grate. Send Gooigi down, and have him shine his blacklight on the righthand wall where there's a missing piece of pipe. Finally, have him flash his flashlight on the flower that grows once the water is flowing to get the gem.

Luigi finds the red gem in the Garden Suites

Luigi finds the red gem in the Garden Suites (Image credit: iMore)

Red: This one's in the Blooming Suite, the bedroom with all the flowers you can use flash on. Use the plunger on the nightstand to reveal a grate and send Googi inside. Have him use flash on the flower on top of the bed to get the gem.

Luigi finds the blue gem in the Garden Suites

Luigi finds the blue gem in the Garden Suites (Image credit: iMore)

Blue: You can see this gem from the very top of the atrium, when you're swinging to reach the top of the flower. Head across the big flower and stand on its left-hand side, then suck with the Poltergust to bring a path to you (you can see the location of the unrollable path from other vantage points). Cross it, then start sucking up the ivy on the wall to reveal a path you can walk through. Head in and follow the path back across the room to get the gem.

Luigi finds the green gem in the Garden Suites

Luigi finds the green gem in the Garden Suites (Image credit: iMore)

Green: In the bedroom with the bouncy mushrooms, suck the curtains off the bed and follow the path you can now see down below the room. Use flash on the flower in the bottom corner, and then again on the other one on the other side of the mushrooms. Send Gooigi through the grate near the top of the room to get the gem that appears.

Luigi finds the purple gem in the Garden Suites

Luigi finds the purple gem in the Garden Suites (Image credit: iMore)

Purple: In the bathroom with all the pink petals/leaves, suck all the nice foliage up to reveal a grate in the bottom left and a gem in the tub. Send Gooigi into the grate to get the gem.

Luigi finds the yellow gem in the Garden Suites

Luigi finds the yellow gem in the Garden Suites (Image credit: iMore)

Yellow: In the hallway off the elevator, walk to the right until you reach the point where the hallway turns and heads up. Shine your blacklight on the painting at the far right of that first part of the hallway and a gem will appear.

8F - Paranormal Productions

Luigi finds the clear gem in Paranormal Productions

Luigi finds the clear gem in Paranormal Productions (Image credit: iMore)

Clear: On the town/fire set, suck up the wrapped bundle on the back of the bicycle to reveal a gem ghost.

Luigi finds the clear gem in Paranormal Productions

Luigi finds the clear gem in Paranormal Productions (Image credit: iMore)

Red: Just outside the entrance to the main studio section, there's a rug with a big number "8" on it. Smash the plant in the corner with your plunger, then blow the carpet back to find the gem.

Luigi finds the blue gem in Paranormal Productions

Luigi finds the blue gem in Paranormal Productions (Image credit: iMore)

Blue: In the backstage area where you first meet the director ghost, have Luigi climb onto the cherry picker while Gooigi vacuums the wheel to lift him up. On the rafters, move carefully (it helps to recall Gooigi here so the camera zooms in closer on Luigi) to the far right of the rafters and collect the block of ice. You can either melt it on the lit torch if you still have it, or carry it through the TV to the town/fire set and have Gooigi melt it in the fire to get the gem.

Luigi finds the green gem in Paranormal Productions

Luigi finds the green gem in Paranormal Productions (Image credit: iMore)

Green: You'll see this one in a big bottle on the Micro Set (with the spider). Gooigi can just go inside and get it.

Luigi finds the purple gem in Paranormal Productions

Luigi finds the purple gem in Paranormal Productions (Image credit: iMore)

Purple: Just outside the elevator, use the vacuum on the helicopter hanging from the ceiling to reveal the gem.

Yellow: Just outside the studio, use the vacuum on the design on the front of the desk and suck up the ball. Send Gooigi through the fence behind the desk to get the gem that appears.

9F - Unnatural History Museum

Luigi finds the clear gem in the Unnatural History Museum

Luigi finds the clear gem in the Unnatural History Museum (Image credit: iMore)

Clear: Break the display case in the bottom right corner of the elevator hall (by the eggs) with either a dinosaur bone or Toad if he's with you, revealing a gem ghost.

Luigi finds the clear gem in the Unnatural History Museum

Luigi finds the clear gem in the Unnatural History Museum (Image credit: iMore)

Red: At the desk right in front of the elevator, use the vacuum on the chair to make it spin and reveal the gem.

Luigi finds the blue gem in the Unnatural History Museum

Luigi finds the blue gem in the Unnatural History Museum (Image credit: iMore)

Blue: On the left side of the elevator hall, head to the top where there are two pillars. One has some plants in front of it, which you can suck up to reveal a light to use flash on for the gem.

Luigi finds the green gem in the Unnatural History Museum

Luigi finds the green gem in the Unnatural History Museum (Image credit: iMore)

Green: Suck up and throw either a dinosaur bone or Toad at the dinosaur hanging above the elevator.

Luigi finds the purple gem in the Unnatural History Museum

Luigi finds the purple gem in the Unnatural History Museum (Image credit: iMore)

Purple: Once again, either a dinosaur bone or Toad can be sucked up and thrown at the bottom left glass case in the elevator hall. Then shine the backlight on the case to reveal the gem.

Luigi finds the yellow gem in the Unnatural History Museum

Luigi finds the yellow gem in the Unnatural History Museum (Image credit: iMore)

Yellow: One last time, throw either Toad or a bone at the glass case just outside the boss fight room and to the right to get the gem inside.

10F - Tomb Suites

Luigi finds the clear gem in Tomb Suites

Luigi finds the clear gem in Tomb Suites (Image credit: iMore)

Clear: In the main room of the pyramid (after you fall through the whole) use your plunger on the sarcophagus in the bottom right to open it. These are set up like nesting dolls, so keep opening them until you find the gem inside.

Luigi finds the red gem in Tomb Suites

Luigi finds the red gem in Tomb Suites (Image credit: iMore)

Red: In the elevator hall, you'll see a statue of a snake at the far end near the door to the pyramid. Break the vase and vacuum up the rope to open its mouth, then have Gooigi suck the gem out.

Luigi finds the blue gem in Tomb Suites

Luigi finds the blue gem in Tomb Suites (Image credit: iMore)

Blue: In the trapped room on the lefthand side of the main pyramid room (with the colored/shape slots and poison gas), there's an extra slot for a cross-shaped peg on the lefthand wall when you first walk in. Break vases in the second room until you find the piece that goes here, then suck it up and shoot it in to reveal the room with the gem inside.

Luigi finds the green gem in Tomb Suites

Luigi finds the green gem in Tomb Suites (Image credit: iMore)

Green: In the trap room with the scale, send Gooigi through the floor drain on the lefthand side and then have him open the chest for the gem.

Luigi finds the purple gem in Tomb Suites

Luigi finds the purple gem in Tomb Suites (Image credit: iMore)

Purple: This one's tricky to find. It's buried in the sand in the pyramid room, on the lefthand side toward the middle/back of the room.

Luigi finds the purple gem in Tomb Suites

Luigi finds the purple gem in Tomb Suites (Image credit: iMore)

Yellow: On the righthand side of the pyramid room, there's a broken snake statue in the sand. Suck up the sand in your way then use your blacklight to reveal the missing segments, which will open the snake's mouth and give you the gem.

11F - Twisted Suites

Luigi finds the clear gem in Twisted Suites

Luigi finds the clear gem in Twisted Suites (Image credit: iMore)

Clear: In the bathroom with the card suit chandelier, as you vacuum you may notice the lights changing above you. This is indicating you're vacuuming up hidden cards around the room. Finding them all gets you the gem, though there are some that are a bit tricky to collect (especially two near the toilet).

Luigi finds the red gem in Twisted Suites

Luigi finds the red gem in Twisted Suites (Image credit: iMore)

Red: In the Bladed Bedroom, vacuum the giant wheel in the back until a bunch of swords come flying at it (look out!) to spawn a gem.

Luigi finds the blue gem in Twisted Suites

Luigi finds the blue gem in Twisted Suites (Image credit: iMore)

Blue: In the room where you found the key in a cage, spin the hoop at the left side of the room with your vacuum to spawn the blue gem.

Luigi finds the green gem in Twisted Suites

Luigi finds the green gem in Twisted Suites (Image credit: iMore)

Green: In the room with the stage, have Luigi suction a panel on the top right, which will open the glass cases around the room very briefly. The gem is on the lefthand side of the room, so you'll have to have Gooigi ready on that side to suck the gem up as soon as it's available.

Luigi finds the purple gem in Twisted Suites

Luigi finds the purple gem in Twisted Suites (Image credit: iMore)

Purple: In the long hallway with the statue of the three magicians, climb into a hat as Luigi and take it to the statue. Use your burst next to the statue to drop the hat onto it, then head up the stairs that appear to find the gem in the chest above.

Luigi finds the yellow gem in Twisted Suites

Luigi finds the yellow gem in Twisted Suites (Image credit: iMore)

Yellow: The bathroom just off the room with the giant mirror has its own mirrors, and you can see a gem portrait you can blacklight reflected in one of them.

12F - The Spectral Catch

Luigi finds the clear gem in the Spectral Catch

Luigi's Mansion 3 (Image credit: iMore)

Clear: Once you enter the main area off the elevator hall, you'll see a skull on the lefthand side of the room with a box beneath it. Blacklight this to reveal a pulley to raise a flag. Vacuum and pull the rope to get the gem.

Luigi finds the red gem in the Spectral Catch

Luigi's Mansion 3 (Image credit: iMore)

Red: In the room with the ocean and the ship, head to the left to see a mermaid statue. Throw three coconuts at it with your vacuum to spawn a gem ghost.

Luigi finds the blue gem in the Spectral Catch

Luigi's Mansion 3 (Image credit: iMore)

Blue: Use the upgraded Poltergust in the elevator hall to suck up the carpet on the righthand side, revealing an X on the floor. Burst the X for a gem.

Luigi finds the green gem in the Spectral Catch

Luigi's Mansion 3 (Image credit: iMore)

Green: In the room with the ocean and the ship, head to the righthand side of the sandy area and keep walking to move the camera. Use the blacklight on the ocean to the right to reveal a bridge to an island, and head over there. Use the blacklight again on the top to reveal a second bridge to the other island. Vacuum up the sand in the center to reveal a chest with the gem.

Luigi finds the purple gem in the Spectral Catch

Luigi's Mansion 3 (Image credit: iMore)

Purple: Follow the directions for the Green gem, but stop on the first island and vacuum up sand to get this gem too.

Luigi finds the yellow gem in the Spectral Catch

Luigi's Mansion 3 (Image credit: iMore)

Yellow: After sucking up the wall in the elevator hall with the upgraded Poltergust, you should see a pipe for Gooigi. Send him in and collect the globe behind he desk with your vacuum. Blow it back over the counter so Luigi can suck it up, then have Luigi aim and shoot it at the cannonballs hanging off the righthand side of the area just outside the elevator.

13F - Fitness Center

Luigi finds the clear gem in the Fitness Center

Luigi finds the clear gem in the Fitness Center (Image credit: iMore)

Clear: In the office overlooking the pool, you can use the blacklight on the desk to reveal a hidden bell. You may have to clear all the other ghosts out of the room first, but if you ring it three times in a row a gem ghost should appear.

Luigi finds the red gem in the Fitness Center

Luigi finds the red gem in the Fitness Center (Image credit: iMore)

Red: This one's in the weight room. There's a staircase you might not be able to see easily in the bottom left that leads up to a separate area. Put Gooigi on the scale at the far end and look in the mirror -- a panel has opened up with a gem inside. Send Luigi down to collect it with the vacuum.

Luigi finds the blue gem in the Fitness Center

Luigi finds the blue gem in the Fitness Center (Image credit: iMore)

Blue: On the lefthand side of the locker room, there's a sign with a person swimming. Suck up a ball or other heavy object and shoot it at the sign for a gem.

Luigi finds the green gem in the Fitness Center

Luigi finds the green gem in the Fitness Center (Image credit: iMore)

Green: Once you clear out the shower room, send Gooigi down the drain. Have him vacuum the valve until the water is gone and he can collect the gem at the bottom.

Luigi finds the purple gem in the Fitness Center

Luigi finds the purple gem in the Fitness Center (Image credit: iMore)

Purple: In the treadmill room, flash the radio three times to get spooky music to play. Ghosts will start working out on the equipment that you can reveal with the blacklight, including a gem ghost.

Luigi finds the yellow gem in the Fitness Center

Luigi finds the yellow gem in the Fitness Center (Image credit: iMore)

Yellow: In the elevator hall, have both Luigi and Gooigi stand on the symbol in the middle of the floor to open the wall on the right. Vacuum up the gem.

14F - Dance Hall

Luigi finds the clear gem in the Dance Hall

Luigi's Mansion 3 (Image credit: iMore)

Clear: This one's a bit detailed, but will open up more than one gem to you. After you defeat the boss, have Luigi and Gooigi each stand on the unlit squares on the dance floor to reveal an outlet for the upgraded Poltergust. Use it to suck up the entire back wall, revealing a secret room. Go inside, and flash the light on the wall to reveal two hidden sets of stairs up to the tables on either side of the dance hall. Exit and go up the lefthand stairs, then walk down until you see a floating lamp above a missing table. Shine your blacklight to reveal the table and a gem ghost.

Luigi finds the red gem in the Dance Hall

Luigi's Mansion 3 (Image credit: iMore)

Red: Follow the instructions for the clear gem, but this time have Luigi and Gooigi each head up the stairs on one side of the dance hall. Have them both vacuum the record on the wall at the top at the same time to reveal this gem.

Luigi finds the blue gem in the Dance Hall

Luigi's Mansion 3 (Image credit: iMore)

Blue: Again follow the instructions for the clear gem until you're in the hidden back room, then vacuum up all the wigs. There's one mannekin that won't get sucked up -- its wig was missing. Shine the blacklight on it to reveal it, then suck it up to get a gem.

Luigi finds the green gem in the Dance Hall

Luigi's Mansion 3 (Image credit: iMore)

Green: Back in the hallway, go behind the counter and vacuum the poster on the left side to access the coatroom. Vacuum up every coat on the left to get the panel to drop out and give you the gem.

Luigi finds the purple gem in the Dance Hall

Luigi's Mansion 3 (Image credit: iMore)

Purple: Still in the hallway, vacuum the turntable on the far left side of the room to make a brick jut out from the wall. In typical Super Mario Bros. fashion, have Luigi burst jump to hit the brick over and over until a gem pops out.

Luigi finds the yellow gem in the Dance Hall

Luigi's Mansion 3 (Image credit: iMore)

Yellow: Right when you exit the elevator, you'll notice a floor section with lit tiles, though some aren't lit. You need to get all the tiles to light up by walking across them, which you can do alone or with Gooigi. This will cause the floor to drop and reveal a hidden area with a gem stuck in a web you can vacuum up.

15F - Master Suite

Luigi finds the clear gem in the Master Suite

Luigi finds the clear gem in the Master Suite (Image credit: iMore)

Clear: Once you're in the set of hallways connecting the rooms containing the four keys, head left. You'll see a portrait of a boo and a weird-looking statue in front of it. Have Luigi interact with the statue and rotate it until the shadow lines up with the picture. Repeat a second time for the gem.

Luigi finds the red gem in the Master Suite

Luigi finds the red gem in the Master Suite (Image credit: iMore)

Red: In the library, head all the way to the bottom, walk to the back, and then left to find a somewhat-hidden room. Vacuum up all the books until you find one that sticks to your vacuum instead of sucking up. Carry it upstairs and place it on the shelf on the right side where there's a missing book.

Luigi finds the blue gem in the Master Suite

Luigi finds the blue gem in the Master Suite (Image credit: iMore)

Blue: In the bathroom, send Gooigi into the drain and follow the path around to the left, where a gem awaits. You'll need to go through a second drain to get up top and collect it.

Luigi finds the green gem in the Master Suite

Luigi finds the green gem in the Master Suite (Image credit: iMore)

Green: In the first room, have both Luigi and Gooigi stand on the tables on either side of the lounge area to get a gem to pop up.

Luigi finds the purple gem in the Master Suite

Luigi finds the purple gem in the Master Suite (Image credit: iMore)

Purple: In the first room, you can see a purple gem in the elvator shaft. To get it, have Gooigi go through a pipe on the righthand side of the shaft (on the outside) that will send him to the top. You can then drop down to collect the gem.

Luigi finds the yellow gem in the Master Suite

Luigi finds the yellow gem in the Master Suite (Image credit: iMore)

Yellow: This one's in the bedroom and accessible once you reveal the big raising and lowering platform. Work your way as high as you can go, then as it descends gently send Gooigi through the bars for this gem. It can be tricky and might take a few tries.

What do you get for collecting all the gems?

The Special Items menu in Luigi's Mansion 3

The Special Items menu in Luigi's Mansion 3 (Image credit: iMore)

There's no gameplay reward for getting every gem, however, you do get a very fancy diamond-encrusted plunger to use, plus an achievement. You can equip the plunger by going to E. Gadd's lab, selecting "Gallary," and choosing "Special Items."

Reb Valentine
With contributions from