11550
The surface oxidation and hydrophobicity of natural enargite ( Cu ( 3 ) AsS ( 4 ) ) and the formation of oxidation species at the mineral surface have been examined by a novel experimental approach that combines electrochemical techniques and atomic force microscopy ( AFM ) .
 Chemical: enargite; Chemical: Cu ( 3 ) AsS ( 4 )
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: enargite; Chemical: Cu ( 3 ) AsS ( 4 )