And not from Broken Hill!
Marshite is a rare copper iodide mineral, originally found at Broken Hill. There is one other locality in Australia where it has been found, and that is the Poona mine, Moonta, South Australia. Worldwide, there are only a handful of localities, the main ones being Chile and Russia.
This specimen is from the Mutooroo mine in South Australia. It comes from the late Bernie Day’s collection and was mislabelled as sphalerite. It didn’t look quite right, so I decided to check it using my Convoy S2+ UV light. The brilliant red response is typical for marshite.
Footnote: Marshite from Broken Hill might not be as rare as first thought. The advent of the Convoy has allowed mineral collectors at shows to locate many more, previously overlooked, specimens. Simply walking around, checking specimens from Broken Hill, in bright daylight(!) shows them up.