original_query: What are the characteristics of geopolymers?
query: What are the characteristics of geopolymers?
answer: Geopolymers are inorganic, typically ceramic, alumino-silicate materials forming long-range, covalently bonded, non-crystalline (amorphous) networks at room temperature.  They are similar to zeolites but amorphous instead of crystalline. Their microstructure is temperature-dependent, evolving into a crystalline matrix above 500°C. They can be synthesized in alkaline or acidic media and are used in various applications due to their fire and heat resistance, among other properties.