I note the online presence of the
Periodico di Mineralogia, "an international journal of mineralogy, crystallography, geochemistry, ore deposits, petrology, volcanology, and applied topics on environment, archaeometry and cultural heritage," based at La Sapienza. There's no explicit statement of open access, but all the issues from 1999 to 2010 are freely downloadable.
The journal's page is located at
http://tetide.geo.uniroma1.it/riviste/permin/permin.html - click on "Issues Year xxxx" in the right hand column to access the issues.
A sampling of articles (all in English, by editorial policy) from 2010 include: