According to Article 24 of the Law on the Protection of Consumers' Rights and Interests, if the goods or services provided by operators do not meet the quality requirements, consumers may return them in accordance with the provisions of the state and the agreement of the parties concerned, or require operators to fulfill the obligation of replacement and repair. If there is no state regulation and agreement between the parties, consumers can return the goods within seven days from the date of receipt.
Therefore, if the goods you bought at the jewelry show have quality problems, you can try to contact the seller or the organizer to return them according to the relevant local regulations and agreements. If the seller or organizer refuses to return the goods, they can seek the help of relevant consumer rights organizations.