Mineraldle
Puzzle #76 was brookite.
Brookite is the orthorhombic variant of titanium dioxide (TiO2), which occurs in four known natural polymorphic forms (minerals with the same composition but different structure). The other three of these forms are akaogiite (monoclinic), anatase (tetragonal) and rutile (tetragonal). Brookite is rare compared to anatase and rutile and, like these forms, it exhibits photocatalytic activity.
Read about it on Wikipedia →
What the record says
Puzzle 76 ran on 29 Sep 2026 and the answer was brookite, played with 6 guesses against 4 columns. On the record: Crystal system - orthorhombic; Strunz group - oxides-hydroxides; Elements - O, Ti; Named after - person.
Beyond the grid the record adds Formula - TiOâ‚‚; Named after - Henry-James Brooke.
Mineraldle builds its record from Wikidata - CC0 1.0. The description above comes from the same place the game credits on every reveal: English Wikipedia verbatim extract, CC BY-SA 4.0. The puzzle itself is still playable in the archive, and every answer that has been and gone is listed on the past-answers page.
How it scored
- Crystal system
- orthorhombic
- Strunz group
- oxides-hydroxides
- Elements
- O, Ti
- Named after
- person
Also on the record
- Formula
- TiOâ‚‚
- Named after
- Henry-James Brooke