Facts
- Chemical formula
- NaNa₂(Fe²⁺₄Fe³⁺)Si₈O₂₂(OH)₂
- Crystal system
- Monoclinic
- Number of elements
- 5
- IMA status
- Redefined
- Type locality
- Kangerluarsuk fjord, Ilímaussaq
- Named after
- Johan August Arfwedson
- Colour
- black
Sources: Wikidata (CC0), IMA list of minerals via Wikidata · Wikidata Q2008960