Mineraldle
Puzzle #49 was colemanite.
Colemanite (Ca2B6O11·5H2O) or (CaB3O4(OH)3·H2O) is a borate mineral found in evaporite deposits of alkaline lacustrine environments. Colemanite is a secondary mineral that forms by alteration of borax and ulexite.
Read about it on Wikipedia →
What the record says
Puzzle 49 ran on 2 Sep 2026 and the answer was colemanite, played with 6 guesses against 4 columns. On the record: Crystal system - monoclinic; Strunz group - borates; Elements - B, Ca, H, O; Named after - person.
Beyond the grid the record adds Formula - CaB₃O₄(OH)₃·H₂O; Named after - William Tell Coleman.
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
- monoclinic
- Strunz group
- borates
- Elements
- B, Ca, H, O
- Named after
- person
Also on the record
- Formula
- CaB₃O₄(OH)₃·H₂O
- Named after
- William Tell Coleman