What is the legal status of a sale where the price is specified by an uncharacterized item, such as a specific camel whose description is unknown?

Primary text

A sale is invalid if an object, such as a specific male camel (*jamal jidha'*) whose description is not known, is stipulated as the price. Ignorance concerning the specification (*sifa*) of the exchanged object is equivalent to ignorance of the object itself, thereby corrupting the contract of sale.