Seems like the magatama categories are a mix of game categories and categories for convenience. I'll try making the categories closer to the game categories over time because the categories aren't manageable as they are now.
Here are some changes I'm planning to make:
Defense->Mineral Magatama
General->Special Magatama
Special->Skill Slot Magatama
(doesn't exist)->Aidama/Oomaga/Warding Magatama (undecided)
(doesn't exist)->Glass Marble
Firon-ingame (talk) 05:48, September 27, 2017 (UTC)