Silver iodide

The compound is a bright yellow solid, but samples almost always contain impurities of metallic silver that give a grey colouration.

Alternatively, dissolution of AgI in a solution of concentrated silver nitrate followed by dilution affords α-AgI.

[10] Unless the preparation is conducted in dark conditions, the solid darkens rapidly, the light causing the reduction of ionic silver to metallic.

The crystalline structure of β-AgI is similar to that of ice, allowing it to induce freezing by the process known as heterogeneous nucleation.

[citation needed] Extreme exposure can lead to argyria, characterized by localized discolouration of body tissue.

Silver iodide
Silver iodide
NFPA 704 four-colored diamond Health 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroform Flammability 0: Will not burn. E.g. water Instability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogen Special hazards (white): no code
The golden-yellow crystals on this mineral sample are iodargyrite , a naturally occurring form of β-AgI.
Cessna 210 equipped with a silver iodide generator for cloud seeding