STRENGITE FePO4·2H2O (orthorhombic) . Crystals are pseudo-octahedral or stout prismatic . Hagendorf/Germany . 紅磷鐵礦晶體細小罕見，假八面體，短柱狀，細小圓球狀，或纖維放射狀．透明玻璃狀， 硬度 3.5~4.5．紫紅色為最高級的色彩．由富含鐵的磷酸鹽類變化而來．礦名來源：Named after the German mineralogist, J. A. Streng (1830-1897).

著名產地：Rio Grande de Norte, Brazil; Bull Moose Mine, Custer, South Dakota, Indian Mountain, Alabama and San Diego Co., California, USA; Svappavaara, Sweden; Eleonore Mine, Germany and Mangualde, Portugal.

經典名礦欣賞．２．３．４．５．６．７．８
NO.456