Cognomen Петра-Оніка (Петра-Оніка 
) , worldwide, is an extremely rare family name. Much more frequently, Петра-Оніка is the forename as well as the last name. Parts of the name also exists independently as a first name Петра, and a last name Оніка.
| VARIANT | COUNTRY |
|---|---|
| Петра-Оніка | Ukraine |