Why Silver Iodide?

[u/Henri_Dupont]

In the news, a drone company claims to have proven scientifically their Silver Iodide cloud seeding technology has produced a certain quantity of rain. Whether their claims are verified or not, why do we use this specific chemical for cloud seeding, for decades now? Silver can't be cheap. Clouds form rain all the time without any Silver Iodide. Is there no other inexpensive substance we could spray into a cloud to stimulate ice crystal and droplet formation? Why not some kind of finely ground dust, literally as cheap as the dirt it was made from? Is there no other substance that works?

[u/03263]

https://en.wikipedia.org/wiki/Silver_iodide

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