
Hornblende-Pegmatit, Antarktische Halbinsel — Photo: Hannes Grobe · CC BY-SA 4.0
Magnesio-hornblende
Also known as: Hornblende.
Magnesio-hornblende is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₂(Mg₄Al)(Si₇Al)O₂₂(OH)₂.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Amphibole structural group.
Key properties: Mohs hardness 5–6; specific gravity 3.137; typically green or black; white streak; Vitreous luster; optically biaxial.
IMA symbol Mhbl, IMA status: approved, named in 1965.
A rock-forming mineral.
Indicates a calcium amphibole with composition between 0.5 and 1.5 apfu C(Al+Fe3++2Ti) and between 0 and 0.5 apfu (Na+K+2Ca).
Collections: Everyday Minerals.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
Browse more M minerals or help write this entry.