Raw Lapis Lazuli has no category listed in its infobox and also does not show up when I filter for Minerals & Ores in the Hoard or Vault.
All other items I've seen, or at least the rock/mineral/ore type ones, have their category listed. For instance, compare Emerald's infobox:
All other items I've seen, or at least the rock/mineral/ore type ones, have their category listed. For instance, compare Emerald's infobox: