Class : Halides
    Subclass : Iodides
    Crystal system : Hexagonal
    Chemistry : AgI
    Rarity : Rare

Iodargyrite (or iodyrite) is a rare silver halide, found in the superficial oxidation zones of silver and silver-bearing galena deposits. It is associated with other silver halides (chlorargyrite, bromargyrite) and with various secondary minerals of iron, lead, silver or zinc, depending on the metals present in the deposit. Its name is linked to its chemical composition. It is a pale yellow to straw yellow mineral, with strong luster, photosensitive, low hardness (1.5 to 2). The crystals are hexagonal prismatic to tabular, or barrel-shaped, usually hemimorphic ; they frequently constitute aggregates in rosettes, parallel groups or globules.

Main photo : Iodargyrite from Broken Hill, Australia © Eugene & Sharon Cisneros

A twin is known on {30-34} and can be fourlings. Paramorph of iodargyrite after miersite show repeated twinning parallel to {111} of the original miersite.

No fakes recorded for this mineral species.