Is the word joia the same in Brazilian and European Portuguese?

No

While the spelling and the literal meaning (jewelry/gemstones) are the same in both varieties of Portuguese, there is a significant difference in typical usage. In Brazil, "joia" is widely used as an informal adjective or interjection to mean "great," "excellent," "cool," or "fine." In Portugal, this slang usage is virtually non-existent; a Portuguese person would almost exclusively use the word to refer to physical ornaments or precious stones.

Brazilian Portuguese Usage

1. Tudo joia com você? (Is everything great with you?)
2. O plano é joia, podemos fazer assim. (The plan is great, we can do it this way.)
3. A comida estava joia! (The food was excellent!)
4. Ele é uma joia de pessoa. (He is a gem of a person.)
5. O atendimento no restaurante foi joia. (The service at the restaurant was great.)

Continental Portuguese Usage

1. Tudo bem com você? (Is everything fine with you?)
2. O plano é fixe! (The plan is cool!)
3. A comida estava ótima. (The food was great.)
4. Ele é uma pessoa fantástica. (He is a fantastic person.)
5. O atendimento no restaurante foi excelente. (The service at the restaurant was excellent.)