Hulsite

Facts

Chemical formula

Fe²⁺₂Fe³⁺O₂(BO₃)

Crystal system

Monoclinic

Mohs hardness

3.0

Elements in formula

Iron, Oxygen, Boron

Number of elements

3

IMA status

Grandfathered

Named after

Alfred H. Brooks

Sources: Wikidata (CC0), IMA list of minerals via Wikidata · Wikidata Q3787559