Mineraldle
Puzzle #39 was zirconolite.
Zirconolite is a mineral, calcium zirconium titanate; formula CaZrTi2O7. Some examples of the mineral may also contain thorium, uranium, cerium, niobium and iron; the presence of thorium or uranium would make the mineral radioactive. It is black or brown in color.
Read about it on Wikipedia →
What the record says
Puzzle 39 ran on 23 Aug 2026 and the answer was zirconolite, played with 6 guesses against 4 columns. On the record: Crystal system - orthorhombic; Strunz group - oxides-hydroxides; Elements - Ca, O, Ti, Zr; Named after - other.
Beyond the grid the record adds Formula - CaZrTi₂O₇; Named after - zirconium.
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
- Ca, O, Ti, Zr
- Named after
- other
Also on the record
- Formula
- CaZrTi₂O₇
- Named after
- zirconium