4784
Pure silicon crystals are very rarely found in nature , but notable exceptions are crystals as large as to 0.3 " mm across found during sampling gases from the Kudriavy volcano on Iturup , one of the Kuril Islands .
 location: Kudriavy; location: Iturup; location: Kuril Islands
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 location: Kudriavy; location: Iturup; location: Kuril Islands