Question: which gem stone is produced by the secretion of some sea creatures
[{'answer': 'pearl', 'provenance': [{'wikipedia_id': '24007', 'title': 'Pearl', 'start_paragraph_id': 1, 'start_character': 2, 'end_paragraph_id': 1, 'end_character': 7, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '24007', 'title': 'Pearl', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 686, 'bleu_score': 0.946243648101975, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6620391964542729717}, 'section': 'Section::::Abstract.'}]}]