Ludlamite is a hydrous iron-manganese phosphate forming bright apple-green to lime-green tabular crystals. It is one of the rarer iron phosphates and a target species for phosphate-mineral specialists.
Properties
- Formula: (Fe,Mn,Mg)3(PO4)2·4H2O
- Crystal system: Monoclinic
- Hardness: 3 – 4
- Color: Apple-green, lime-green, sometimes colorless or pale
- Streak: Pale green to white
- Luster: Vitreous to pearly
- Cleavage: Perfect on {001}
- Density: 3.1 – 3.2 g/cm³
Occurrence
Type locality: Wheal Jane (Cornwall, UK). World-class material: Blackbird Mine (Idaho) for large green crystals; Llallagua (Bolivia) for sharp wedges on cassiterite/wolframite; Hagendorf (Germany) for pegmatite specimens.
Identification
Apple-green tabular prisms + association with iron phosphate environments (cassiterite-wolframite veins or granite pegmatites). Distinguish from triphylite (lithium phosphate, harder) and vivianite (different chemistry, often deep blue).
Collector Notes
Llallagua ludlamite on wolframite/cassiterite matrix is a classic collector pairing. Llallagua specimens with sharp green crystals on dark hosts are top-tier.
Found at these Localities
- Llallagua (Siglo XX) (亚亚瓜矿)
- Cornwall Mining District (康沃尔矿区)
