Facts
- Chemical formula
- Fe²⁺Fe³⁺₂Al₃(PO₄)₄(OH)₅(H₂O)₄·2H₂O
- Crystal system
- Monoclinic
- Elements in formula
- Iron, Aluminium, Phosphorus, Oxygen, Hydrogen
- Number of elements
- 5
- IMA status
- Approved
- Type locality
- Huber stock
- Named after
- Jaromír Tvrdý
Sources: Wikidata (CC0), IMA list of minerals via Wikidata · Wikidata Q19862360