[1] Its composition consists of lead (48.35%), oxygen (18.67%), arsenic (17.48%), zinc (18.99%), and contains a negligible amount of hydrogen (0.24%).

Unlike descloizite, arsendescloizite has no trace of vanadium in its composition whatsoever, thus it became quickly obvious that the mineral was from a new species.

The specimen Pete and Paul were studying was found on a matrix of a copper ore that mainly consisted of tennantite.

This was weird due to the fact that it occurs with the calcium-rich mimetite and was found on a copper ore.[2] Arsendescloizite's type locality is at the Tsumeb mine, Namibia.

Arsendescloizite occurs in oxidized hydrothermal polymetallic deposits as a secondary mineral.