Grand Lobby

The Grand Lobby is an area in Luigi's Mansion 3. It is located on the first floor of The Last Resort, above Basement 1. It is the first area to be explored in the game. At the start of the game, the lobby is bright, colorful, and lit up, with presents and staff everywhere. There are also pictures hanging from the ceiling of Luigi, Mario, Princess Peach, and Toad. Most parts of the Grand Lobby are inaccessible at this time, including the elevator and the stairs to the second floor. Luigi must talk to the person at the front desk to check in. Hellen Gravely then appears and escorts them up to their rooms on the fifth floor, the RIP Suites.

The next time the Grand Lobby is visited, it undergoes major changes. It is much darker and less colorful. There are Jack O' Lanterns scattered across the floor, and the swan ice sculptures are now gargoyles. The pictures above now have X's over them. Luigi discovers two Goobs barring up the front door and defeats them. Polterpup then leads him up to the second floor, where they find Professor E. Gadd trapped in a painting.

Gem locations
There are 6 gems in the Grand Lobby which are shaped like diamonds. Luigi cannot get every gem until after he has gotten the Dark-Light Device, has learned the Suction Shot, and has teamed up with Gooigi.
 * Diamond: Found in an invisible couch below the far left window. Luigi must use the Dark-Light Device to make it appear along with a ghost. He can then defeat the ghost and collect the gem.
 * Ruby: Hidden in a picture to the right of the stairs. Luigi must use the Suction Shot on the desk below. The picture will then split open, revealing the gem.
 * Sapphire: Found above the desk to the left of the lobby. Luigi must walk to the left of the staircase and vacuum the carpet to reveal a grate in the floor. Gooigi must then drop through the grate and dislodge the gem with a Burst, allowing Luigi to collect it.
 * Emerald: Stuck in the plant to the right of the elevator. Luigi must use the Suction Shot to destroy the plant, then collect the gem.
 * Amethyst: Hidden behind the front desk. To access the area behind, the player must use a Burst to open the desk gate. Luigi must flash the safe with the Strobulb to reveal the gem.
 * Citrine: Hidden in the chandelier. Luigi and Gooigi must activate, then stand on the pressure plates in the lobby, then aim up and vacuum the chandelier to reveal several coins and the yellow gem.