Mineraldle
Puzzle #90 was lonsdaleite.
Lonsdaleite, also called hexagonal diamond in reference to the crystal structure, is an allotrope of carbon with a hexagonal lattice, as opposed to the cubical lattice of conventional diamond. It is found in nature in meteorite debris; when meteors containing graphite strike the Earth, the immense heat and stress of the impact transforms the graphite into diamond, but retains graphite's hexagonal crystal lattice.
Read about it on Wikipedia →
What the record says
Puzzle 90 ran on 13 Oct 2026 and the answer was lonsdaleite, played with 6 guesses against 4 columns. On the record: Crystal system - hexagonal; Strunz group - native-elements; Elements - C; Named after - person.
Beyond the grid the record adds Formula - C; Named after - Kathleen Lonsdale.
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
- hexagonal
- Strunz group
- native-elements
- Elements
- C
- Named after
- person
Also on the record
- Formula
- C
- Named after
- Kathleen Lonsdale