Which XRD peak lists are the best?
Webmineral, Ruff, Mindat, Mineralienatlas can differ, f.i. reyerite, truscottite.

Thanks for your comments.
Milo

They all will have variations. The data is only as good as the lab/researcher collecting it. The ASTM JCPDS data files are best, but very expensive. I like RRUFF, but it is still in development

Henry Barwood
Troy University
Troy, Alabama USA

The best is the one that you calculate from a crystal structure (data files for a lot of minerals, even though not all, can be downloaded from the American Mineralogist Crystal Structure Database - check link on each Mindat mineral page).
The RRUFF database offers measured downloadable datasets which might be helpful if there is preferred orientation.