metallis
metallis is a Latin form of metallum, meaning “metal; mine”. It is the ablative plural neuter noun or dative plural neuter noun.
Found 26 times in the Latin texts on Socratos.
Where it is used
Vergil, Aeneid 10.174: insula inexhaustis Chalybum generosa metallis.
All forms of metallum (declension table)
Source: Socratos (socratos.org), a free reader for Ancient Greek and Latin. Grammar from the Perseus Treebank and Morpheus; dictionary entries from Lewis & Short, A Latin Dictionary (Perseus Digital Library, CC BY-SA). Counts are from the texts on Socratos.