Phosphosiderite
Phosphosiderite · Collector Mineral / Semi-Precious Gemstone
Crystal System
Monoclinic; crystals are typically prismatic but more commonly occur as massive or botryoidal aggregates, as seen in this tumbled form.
Mineral Group
Phosphates (Metavariscite group)
Chemical Formula
FePO4·2H2O (Hydrous iron phosphate)
Formation Process
Hydrothermal or secondary alteration mineral. It forms through the oxidation of primary phosphate minerals in granitic pegmatites.
About This Crystal
An opaque, matte to vitreous tumbled stone showcasing a distinct lavender-lilac color with subtle pale pink and yellowish-brown veining or inclusions.
Physical Characteristics
Color: Lavender, purple, or orchid; Streak: White; Cleavage: Good in one direction; Fracture: Conchoidal to uneven; Specific Gravity: 2.74-2.76; Fluorescence: None usually reported.
Optical Properties
Refractive Index: 1.692-1.738; Birefringence: 0.0350-0.0540; Pleochroism: Strong (rose-red to reddish-brown); Opaque in bulk form.
Hardness & Durability
Origin Region
Notable sources include Chile (La Serena), Argentina, Germany, and the USA. It typically forms as a secondary mineral in pegmatites.
Hardness & Durability
Mohs Hardness: 3.5 to 4. Good for decorative use but soft for jewelry; should be protected from scratches and hard impacts.
Care & Maintenance
Clean only with warm, soapy water and a soft cloth. Avoid ultrasonic cleaners, steam, and harsh chemicals. Store separately from harder stones like quartz.
Rarity & Value
Relatively uncommon. Value is based on the richness of the purple hue and the lack of excessive brown matrix; generally affordable but premium for bright lavender.
Special Characteristics
Sometimes contains yellow 'cacoxenite-like' inclusions or light yellow veins of iron oxides that create a 'mosaic' or 'phantom' appearance.
Lore & History
First described in 1890; the name is derived from its phosphate and iron components. Traditionally used in modern crystal healing for its believed calming energy and connection to the third eye and heart chakras.