Volcanic sublimate

A volcanic sublimate or fumarolic sublimate is a mineral which forms directly from volcanic gas, by the process of deposition, during an eruption or discharge from a volcanic vent or fumarole.^[1] Native sulfur is a common sublimate mineral and various halides, sulfides and sulfates occur in this environment associated with fumaroles and eruptions.

References

1. Manahan, Stanley E. Environmental Chemistry, CRC Press, 2004, Eighth Edition, p. 408 ISBN 978-1566706339