The Quiz: What is one of the few rocks known to be able to float on water?
A Pumice
B Feldspar
C Pyrite
Pumice forms when a super-heated, pressurized rock is ejected from a volcano. Once it cools, it can be upwards of 85% porous. These air pockets allow the rock to float, possibly for years, until it becomes waterlogged and sinks.
The correct answer to this quiz is Pumice.