Mineraldle
Puzzle #41 was leucite.
Leucite (from the Greek word leukos meaning white) is a rock-forming mineral of the feldspathoid group, silica-undersaturated and composed of potassium and aluminium tectosilicate KAlSi2O6. Crystals have the form of cubic icositetrahedra but, as first observed by Sir David Brewster in 1821, they are not optically isotropic, and are therefore pseudo-cubic. Goniometric measurements made by Gerhard vom Rath in 1873 led him to refer the crystals to the tetragonal system.
Read about it on Wikipedia →
What the record says
Puzzle 41 ran on 25 Aug 2026 and the answer was leucite, played with 6 guesses against 4 columns. On the record: Crystal system - tetragonal; Strunz group - silicates; Elements - Al, K, O, Si; Named after - other.
Beyond the grid the record adds Formula - K(AlSi₂O₆); Named after - white.
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
- tetragonal
- Strunz group
- silicates
- Elements
- Al, K, O, Si
- Named after
- other
Also on the record
- Formula
- K(AlSi₂O₆)
- Named after
- white