It's found in evaporites (rock salt, potash deposits etc.) and was first described in Kazakhstan in 1966. It's subsequently been found in Canada and Siberia, and now we may be able to add North Yorkshire to the list of Volkovskite finds, with this specimen mined about 1350 metres under Runswick. If so (with all the health warnings above), it's a bit of a first to be announced on this blog.
Volkovskite is transparent, vitreous, clear or pink, has a hardness of 2.5 on the mohr scale and was named after A. I. Volkovskaya, the Russian petrographer. All that clever stuff was lifted from mindat.org's page on Volkovskite. Any proper geologists out there, feel free to pitch in. I've been wrong about things in rocks before.
Update; apparently Volkovskite is an unwelcome find for those whose job is to process potash deposits because it clogs the pumps used in processing. The other recently found mineral boracite is a pest because it's hard.