Jewelry appraisal is an engineering major, and it is technology. In marketing, some people can do without learning, but they may not be able to have both. What they have learned from me is gems and materials technology, including jewelry design. Jewelry appraisal, materials, etc. ~ self-study marketing. Similarly ~ personally, marketing is more important than market and experience ~ and it is easy to learn ~ but identification is not available to everyone. . . You can weigh it yourself ~ it's better to identify the promising ones ~ it would be better if you could design them ~