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 8F 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 – Elevator Hall
As soon as you step out of the elevator, use your vacuum on the helicopter which is hanging above to your left. The helicopter will lower and one of the doors will open and throw out the Purple Gem.
Gem #2 – Studio Entrance
Use your vacuum on the reel at the front of the desk to latch on to the ball on its left hand side, then press A (as if you were performing a Suction Shot) to make the reel spin. This will open up a secret compartment behind the desk which the Yellow Gem will drop out of. Become Gooigi to slip through the gate at the side of the desk to get behind it, then grab your prize.
Gem #3 – Studio Entrance
In the same room, head on over to the bottom left corner and you’ll see a plant in a pot. Perform a Sucker Shot on the pot to destroy it and you’ll notice that the corner of the carpet underneath is lipped up slightly. Use your vacuum on it and walk backwards to roll the carpet back, and a contraption will raise from the ground and drop out the Red Gem.
Gem #4 – Backstage
When you have the lit torch, take it into the Backstage area by travelling through the TV. Drop it on the floor anywhere, then climb up the small ladder in the upper left corner of the room to get on to the lift. Summon Gooigi and use his vacuum on the valve to raise the lift, then take control of Luigi again once you reach the rafters at the top. You’ll notice that a block of ice sits on the rafters in the near right corner. Carefully work your way around there with Luigi and knock the block to the ground below. Then, head back down, use your vacuum to pick up the torch, and hold it over the block of ice until it melts and reveals the Blue Gem.
Gem #5 – Studio 3: Fire Set
Head through the doorway in the top left corner of the room to get on to Studio 3, which is the Fire Set. Walk on to the set and head on over to the bicycle which is in the upper right corner next to the fire hydrant. Vacuum up the cloth which is sitting on top of the basket on the front of the bicycle and a ghost will appear. Defeat this ghost and you’ll be rewarded with the Clear Gem.
Gem #6 – Studio 4: Micro Set
Now go into the room beneath Studio 3, which is Studio 4: Micro Set. You’ll see the Green Gem sitting in a big glass bottle which is laying down. Take control of Gooigi and walk into the top of the bottle and he’ll squeeze his way inside, allowing you to grab the gem.
And that’s it! Congratulations, you collected all six gems.