Mineraldle
Puzzle #85 was ekanite.
Ekanite is an uncommon silicate mineral with chemical formula Ca2ThSi8O20 or (Ca,Fe,Pb)2(Th,U)Si8O20. It is a member of the steacyite group. It is among the few gemstones that are naturally radioactive.
Read about it on Wikipedia →
What the record says
Puzzle 85 ran on 8 Oct 2026 and the answer was ekanite, played with 6 guesses against 4 columns. On the record: Crystal system - tetragonal; Strunz group - silicates; Elements - Ca, O, Si, Th; Named after - other.
Beyond the grid the record adds Formula - Ca₂ThSi₈O₂₀; Named after - human.
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
- Ca, O, Si, Th
- Named after
- other
Also on the record
- Formula
- Ca₂ThSi₈O₂₀
- Named after
- human