23368
From the combination of magnetic and structural studies by means of Fe K - edge X - ray absorption near edge structure ( XANES ) and high - resolution transmission electron microscopy we have identified and quantified two phases of Fe ( ferrihydrite and magnetite ) involved in the biomineralization process , confirming the role of ferrihydrite as the source of Fe ions for magnetite biomineralization in M . gryphiswaldense .
 Chemical: Fe; Chemical: ferrihydrite; Chemical: magnetite; Chemical: ferrihydrite; Chemical: Fe; Chemical: magnetite
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Fe; Chemical: ferrihydrite; Chemical: magnetite; Chemical: ferrihydrite; Chemical: Fe; Chemical: magnetite