Mineraldle

Puzzle #27 was fayalite.

Fayalite is the iron-rich end-member of the olivine solid-solution series. In common with all minerals in the olivine group, fayalite crystallizes in the orthorhombic system with cell parameters a = 4.82 Å, b = 10.48 Å and c = 6.09 Å.

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From Wikipedia (CC BY-SA 4.0)

What the record says

Puzzle 27 ran on 11 Aug 2026 and the answer was fayalite, played with 6 guesses against 4 columns. On the record: Crystal system - orthorhombic; Strunz group - silicates; Elements - Fe, O, Si; Named after - place.

Beyond the grid the record adds Formula - Fe²⁺₂SiO₄; Named after - Faial Island.

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
silicates
Elements
Fe, O, Si
Named after
place

Also on the record

Formula
Fe²⁺₂SiO₄
Named after
Faial Island

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