Question: tanzania is the only country in the world with a unique gemstone called
[{'answer': 'Tanzanite', 'provenance': [{'wikipedia_id': '308210', 'title': 'Tanzanite', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 9, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]