IMA mineral species

Grunerite

☐Fe²⁺₂Fe²⁺₅Si₈O₂₂(OH)₂

Mg-Fe-Mn-amphibole, double chain inosilicate mineral.

Green Brown Gray

Grunerite specimen — Gruenerite Schist Metamorphic Rock North of Keystone, South Dakota 2916.jpg · Wikimedia Commons (see file page for author & license)

Properties

🔷 Monoclinic

Chemical formula	☐Fe²⁺₂Fe²⁺₅Si₈O₂₂(OH)₂
Elements	Fe, Si, O, H
Crystal system	Monoclinic
Mohs hardness	—
Density	—
Streak	—
Color	—
Cleavage	{110}
IMA symbol	Gru
Nickel–Strunz class	9.DE.05

“—” means no reliable value in Wikidata yet. Check Mindat for full data.

Varieties & related stones

Amosite

Learn more

Grunerite on Mindat.org
Wikipedia article
Wikidata item Q420442 (source of this page's data – you can correct it there)