Almandine (Fe₃Al₂(SiO₄)₃) is the iron-rich end-member of the garnet group and the most common garnet species. Its deep wine-red to brownish-red dodecahedral crystals are widely collected and produce classic garnet sand and metamorphic-rock crystal accumulations. Almandine forms in regional metamorphic schists and gneisses, where it grows as well-formed isometric crystals embedded in a matrix of mica and quartz.
Key Facts
- Mohs hardness 7–7.5.
- Isometric (cubic) symmetry; classic dodecahedral and trapezohedral crystal habits.
- Specific gravity ~4.3 — heavy for a non-metallic mineral.
- Diagnostic deep-red to purplish-red color from iron.
- Forms a continuous solid-solution series with pyrope and spessartine within the pyralspite garnet sub-group.
Notable Localities
Anantnag (Kashmir, India), Idaho garnet mines (USA), and Salida (Colorado) are classic sources. China hosts collector-grade material in Xinjiang and Inner Mongolia metamorphic belts.
Found at these Localities
- Inner Mongolia (内蒙古)
- Maharashtra Deccan Traprock Zeolites (马哈拉施特拉德干玄武岩沸石产地)
Available Products of Almandine
4 available specimens
Other Members of the Garnet Group
石榴石族
- Andradite (钙铁榴石)
- Grossular (钙铝榴石)
- Pyrope (镁铝榴石)
- Spessartine (锰铝榴石)
- Uvarovite (钙铬榴石)
