When Marble Beans were initially released in the Cute Fuzzy Animals update, two of them could be crafted with one Marble. This was changed in a later update.
This item seems to be inspired by the magic bean in the Jack and the Beanstalk fairy tale. This is supported by multiple characters' quotes.
While the change log for the March 2022 QoL update noted that the Marble Bean was moved to the Alchemy Engine, this was already the case before the update.
Attention: The following categories are only for the players look up the page based on their first impression, they have nothing to do with the actual categories/behavior/function/tags of these items