FePO4 is a quartz analogue that presents also an alpha-beta phase transitio
n from a P622 to a P32 phase. We describe in this paper the works done in v
iew of obtaining single crystals, and discuss results showing that an incom
mensurate phase takes place in between alpha and beta phases in a range of
17 C. The main alpha-beta transition appears to be closer to the tricritica
l point than in quartz and berlinite.