Re: How hot does it need to get before pumice melts?

Dear Alex,

The melting temperature of pumice is between 880 and 990 degrees Celsius.  
That translates to 1616 to 1814 degrees Fahrenheit (see conversion 
calculations below).

(880 degrees C)(9/5) + 32 =  1616 degrees Fahrenheit.  
(990 degrees C)(9/5) + 32 =  1814 degrees Fahrenheit.

The wide range in the melting temperature of pumice occurs because it has a 
wide range of mineral compositions. A lot of rocks (like granite and basalt 
lava) have ranges in their melting temperatures for the same reason. 

Reference: Hall, Anthony, 1996. Igneous Petrology, Second Edition. Longman 
Group Limited, Essex, England.

Thanks for the question, Alex!