tourmalines - Robuta Search

https://www.gia.edu/gems-gemology/summer-1985-tourmaline-brazil-proctor

A further article exploring tourmaline mines in another part of Minas Gerais.

https://www.bijouxvirginiaforest.com/product-page/papillon-de-tourmalines

Pendentif en argent 925 en forme de papillon serti de 4 tourmalines roses et d'une tourmaline verte.