Mitridatite , Purpurite Locality: Pack Rat Mine, Mt. Tule, Jacumba District, San Diego County , California , USA ( Locality at mindat.org ) Size: small cabinet, 7.1 x 6.7 x 2.5 cm Purpurite and Mitridatite A richly colored massive specimen with golden mitridatite and purple purpurite all over it. Quite rare material for San Diego and a nice study specimen. Ex. Tim Sherburn collection from Cal Graeber as a gift in 1994. Collected by Gary Wallace earlier that year. 7.1 x 6.7 x 2.5 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Mitridatite
Mitridatite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Ca₂Fe³⁺₃O₂(PO₄)₃·3H₂O.
It crystallizes in the monoclinic crystal system (space group Aa). It is a member of the Arseniosiderite structural group.
Key properties: Mohs hardness 2.5; specific gravity 3.24; Olive-green streak; Dull, earthy to resinous luster; optically biaxial.
IMA symbol Mit, grandfathered status — known before the IMA’s founding, named in 1914.
A common stain or crust on minerals near oxidizing ferrous phosphate minerals, typically triphylite or vivianite in granite pegmatite; a component of cement or fossil replacements in some ferruginous oölitic sediments; in phosphatic soils.
It is found associated with Triphylite, vivianite, rockbridgeite, heterosite, huréaulite, fairfieldite, cyrilovite, jahnsite, collinsite, apatite, iron hydroxides.
The name refers to Mt. Mithridat [named for King Mithridates], within the city of Kerch, Ukraine, near which the first specimens were collected.