Gem and material technology is a science and engineering major: science students can apply; Art design belongs to the art category: art students can apply. There are strict rules for voluntary reporting, and cross-reporting is not allowed.
The situation in my school is that if you are a science student and want to apply for an art major, you can ask yourself whether you can change your major after being admitted to the school (provided that your grades are good). Generally, you have to pass some art exams before you can change your major. But I don't know much about it.
Art design will involve the knowledge of jewelry identification, and will teach you how to identify gems with instruments, while the knowledge of geology and crystallography of gems is hardly taught; However, there is nothing about jewelry design except the general appreciation of gems and materials.
Because you want to be a jewelry designer, focusing on the design and production of jewelry, and you have artistic skills. I suggest you focus on jewelry design.
Note: Students majoring in art and design can also take the jewelry appraisal certificate.