The Rubrub Room appears in the game Hamtaro: Ham-Ham Heartbreak. In the room, the player can polish rocks they find.
The rocks can become gems, sunflower seeds or acorns. Alternatively, rocks may disappear after the player polishes them. If the rock becomes a gem, it can be made into jewellery in the accessory room. Hamtaro or Bijou can then wear the accessory in question, in the dress-up room, and can get take their picture, which will replace the title screen when taken.
| Rocks | Rarity |
|---|---|
| Ammonite | 1 star |
| Banana Stone | 1 star |
| Crystal | 1 star |
| Dino Fossil | 1 star |
| Glass Beat | 1 star |
| Amethyst | 2 stars |
| Berry Stone | 2 stars |
| Feather Stone | 2 stars |
| Garnet | 2 stars |
| Peridot | 2 stars |
| Storm Stone | 2 stars |
| Sweet Stone | 2 stars |
| Aquamarine | 3 stars |
| Cheese Stone | 3 stars |
| Cube Stone | 3 stars |
| Opal | 3 stars |
| Pearl | 3 stars |
| Topaz | 3 stars |
| Turquoise | 3 stars |
| Diamond | 4 stars |
| Emerald | 4 stars |
| Ruby | 4 stars |
| Sapphire | 4 stars |
| Ice Stone | 5 stars |
| Peace Moon | 5 stars |
| Rainbow Stone | 5 stars |
| Sun Stone | 5 stars |
| Uni Star | 5 stars |
| Wave stone | 5 stars |