mineral dalam kelas amfibol asbestos, digunakan untuk industri, tetapi kini dibatasi karena menyebabkan asbestosis dan bentuk kartker tertentu, seperti mesotelioma. Disebut juga brown asbestos.

Merriam-Webster Online Dictionary
amosite (noun)
an iron-rich amphibole that is a variety of asbestos
amosite (Wikipedia)
Gruenerite Schist Metamorphic Rock North of Keystone, South Dakota 2916.jpg
Grunerite from South Dakota
Category Inosilicate
(repeating unit)
Strunz classification 9.DE.05
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H-M symbol)
Space group C2/m
Formula mass 1,001.61 g/mol
Color Ashen, brown, brownish green, dark gray
Crystal habit Columnar
Mohs scale hardness 5 - 6
Luster Vitreous
Streak Colorless
Diaphaneity Translucent to opaque
Specific gravity 3.45
Density 3.4 - 3.5
Ultraviolet fluorescence Non-fluorescent
Other characteristics Not radioactive

Grunerite is a mineral of the amphibole group of minerals with formula Fe7Si8O22(OH)2. It is the iron endmember of the grunerite-cummingtonite series. It forms as fibrous, columnar or massive aggregates of crystals. The crystals are monoclinic prismatic. The luster is glassy to pearly with colors ranging from green, brown to dark grey. The Mohs hardness is 5 to 6 and the specific gravity is 3.4 to 3.5.

It was discovered in 1853 and named after Emmanuel-Louis Gruner (1809–1883), a Swiss-French chemist who first analysed it.