Yesterday's answer
Mineraldle was kernite.
Kernite, also known as rasorite, is a hydrated sodium borate hydroxide mineral with formula Na2B4O6(OH)2·3H2O. It is a colorless to white mineral crystallizing in the monoclinic crystal system typically occurring as prismatic to acicular crystals or granular masses. It is relatively soft with Mohs hardness of 2.5 to 3 and light with a specific gravity of 1.91. It exhibits perfect cleavage and a brittle fracture.
Read about it on Wikipedia →
What the record says
Puzzle 98 ran on 21 Oct 2026 and the answer was kernite, played with 6 guesses against 4 columns. On the record: Crystal system - monoclinic; Strunz group - borates; Elements - B, H, Na, O; Named after - place.
Beyond the grid the record adds Formula - Na₂B₄O₆(OH)₂·3H₂O; Named after - Kern County.
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, H, Na, O
- Named after
- place
Also on the record
- Formula
- Na₂B₄O₆(OH)₂·3H₂O
- Named after
- Kern County