Mineraldle
A daily mineral puzzle scored on crystal system, Strunz group, elements and namesake
Mineraldle gives you six guesses to name one of 777 minerals. The grid is only four columns wide, and two of those columns are classification schemes rather than plain facts.
How a round goes
Type a mineral name and the row fills with Crystal system, Strunz group, Elements and Named after. There is no picture, and hardness is deliberately kept out of the grid. Guesses are evaluated on the server, so the page never holds the answer before you finish.
Crystal system is where most players start, because it is a clean seven-way split: triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal and cubic. Monoclinic and orthorhombic are the crowded ones, so a hit there still leaves a large part of the pool standing.
The Strunz group and the Elements column
Strunz group is the top level of the Nickel-Strunz classification, taken from the leading class number of the mineral's Strunz code. Its ten families are native elements, sulfides and sulfosalts, halides, oxides and hydroxides, carbonates and nitrates, borates, sulfates and related minerals, phosphates and related minerals, silicates, and organic compounds. A handful of minerals carry no usable Strunz code and read as unknown, and the grid prints the family as a short code rather than the full name. Silicates are the largest family in the pool by a wide margin, so a silicate hit is weaker information than a borate one.
Elements is the unusual column. It is a set, parsed straight out of the chemical formula, keeping only valid periodic-table symbols and ignoring counts, subscripts, brackets, hydrate dots and charges. A guess that shares no element with the answer is a miss, a guess that shares at least one is a partial, and only an identical set of elements scores as a full hit. Guessing something with a short formula early is a cheap way to test for a single element.
Named after does not tell you the namesake. It tells you what kind of thing it was: a person, a place, or something else, or unknown where Wikidata records no namesake at all. Person and something-else are near-equally common across the pool, so either narrows the field far less than a place does.
Where the data comes from
Names, classifications, formulas, namesakes and hardness values come from Wikidata under CC0 1.0. The reveal reproduces the mineral's verbatim English Wikipedia extract under CC BY-SA 4.0, with a link to the article it was taken from.
After the puzzle, the bonus rounds work over other minerals in the pool: which element a printed formula contains, which mineral belongs to a named Strunz family, and which mineral was named after a given person or thing. On the rare day when both drawn minerals have a sourced hardness, a fourth round asks which is harder on the Mohs scale. Hardness never appears in the guess grid, and where Wikidata records one it shows on the reveal.
Questions
Is it the same puzzle for everyone?
Yes. One mineral a day, the same one for every player, rolling over at midnight UTC. The frozen calendar runs for 777 days, one for each mineral in the pool.
Do I need an account?
No. There is no sign-up. Your streak and your stats are kept in your browser's local storage, so clearing site data for the domain clears them.
Do I need to read chemical formulas?
It helps, but it is not required. The Elements column prints the symbols for almost every guess you make, so you can work out the answer's chemistry by elimination without ever seeing a formula. A few minerals have no parseable formula on record and read as unknown. Where Wikidata records one, the full formula appears on the reveal.