word-forming element indicating origin or derivation from, from French -ite and directly from Latin -ita, from Greek -ites (fem. -itis), word-forming element making adjectives and nouns meaning "connected with or belonging to." Especially used in classical times to form ethnic and local designations (for example in Septuagint translations of Hebrew names in -i) and for names of gems and minerals.
also Petronella, fem. proper name, a Medieval Latin feminine diminutive of Latin Petronius (which is of uncertain origin). Also "the name of a saint much-invoked against fevers and regarded as a daughter of St. Peter. The name was accordingly regarded to be a derivative of Peter and became one of the most popular of girls' names, the vernacular Parnell being still used as a proper name as late as the 18th century in Cornwall" [Reaney]. The shorter form is via Old French Peronelle. By late 14c. it also had become a type-name for "a common woman, a prostitute, a priest's concubine."
<a href="https://www.etymonline.com/word/Parnellite">Etymology of Parnellite by etymonline</a>
Harper, D. (n.d.). Etymology of Parnellite. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/Parnellite