Collection: Anthophyllite

Anthophyllite is a mineral of the amphibole group , more precisely a magnesium and iron silicate belonging to the isomorphic anthophyllite-gedrite series . It is best known for its industrial use in certain types of asbestos , although it is rarer than other types such as chrysotile.

🧪 Chemical formula:

• (Mg,Fe)₇Si₈O₂₂(OH)₂

The composition varies depending on the proportion of magnesium and iron.

📌 Physical characteristics:

• Color : grayish, brownish, greenish

• Luster : Vitreous to silky

• Crystal system : orthorhombic

• Hardness (Mohs) : 5.5 to 6

• Density : 2.85 to 3.2

• Cleavage : perfect to good

• Appearance : prismatic crystals or fibrous aggregates

🌍 Origin and deposits:

Anthophyllite forms in magnesium-rich metamorphic rocks , such as ultramafic rocks or schists . It is often found in:

• Scandinavia (Norway, Finland)

• United States (North Carolina)

• Sri Lanka

• South Africa

🧭 Not to be confused with:

• Gedrite : an amphibole richer in aluminum, very similar chemically

• Actinolite or tremolite : other amphiboles which can also occur in fibrous form