Mineraldle
Puzzle #12 was quartz.
Quartz is a hard mineral composed of silica (silicon dioxide). Its atoms are linked in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen atom being shared between two tetrahedra, giving an overall chemical formula of SiO2. Therefore, quartz is classified structurally as a framework silicate mineral and compositionally as an oxide mineral.
Read about it on Wikipedia →
What the record says
Puzzle 12 ran on 27 Jul 2026 and the answer was quartz, played with 6 guesses against 4 columns. On the record: Crystal system - trigonal; Strunz group - oxides-hydroxides; Elements - O, Si; Named after - other.
Beyond the grid the record adds Formula - SiOâ‚‚; Mohs hardness - 7; Named after - cross vein.
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
- trigonal
- Strunz group
- oxides-hydroxides
- Elements
- O, Si
- Named after
- other
Also on the record
- Formula
- SiOâ‚‚
- Mohs hardness
- 7
- Named after
- cross vein