According to thermodynamics, more ordered states are favoured at lower temperatures, so essentially what you are looking for is a system which increases in volume as it becomes more ordered, which is unusual. As mentioned in another answer, this happens when beer turns to ice, but the volume change is quite small. Another process is as follows:
Hydrogen sulphide generated in oil refinery desulphurisation processes is converted to sulphur by the Claus process:
H2S + 1.5O2 (air) -> SO2 + H2O
2H2S + SO2 -> 3S2 + 2H2O
Sulphur made in this way contains short chain like molecules of the form H-S-..-S-H. As it cools, these decompose to form ordered stable S8 rings with the release of H2S gas. Vessels containing molten sulphur made by this process must be properly vented to ensure they do not overpressure and explode as the sulphur cools. Ihe H2S (hydrogen sulphide, rotten egg gas) presents additional hazards as it is smelly and highly toxic.
A quick google search found this document discussing the handling of this type of sulphur, see pages 4-5. http://www.trimeric.com/assets/15v07-mcintush-molten-sulfur-storage-tank-loading-and-vapor-ejection-systems-review.pdf
EDIT: a better reference http://pubs.acs.org/doi/abs/10.1021/ie50477a047?journalCode=iechad
The other source of sulphur on Earth is via mining, including surface deposits in the craters of semi active volcanoes. I think it quite plausible that sulphur mined on a planet with a high atmospheric pressure such as Venus would contain these H2Sx molecules. As an aside, note that the best place in the solar system for mining sulphur is probably be https://en.wikipedia.org/wiki/Io_(moon) though it has only a trace atmosphere so I would expect the sulphur there to be fully degassed.