3 main, not sure if there's other devices. (seismoscope, seismometer, ???)
There are thousands, depending upon how you classify them. The simplest division is Igneous/Plutonic, Sedimentary, and Metamorphic. Beyond this you may classify them as carbonates, sulphates and so...
There are loads of different types of fossils :).
there are so many fireworks that they can not count them
There about 1,300 species worldwide, with 13 species native to the US.
a lot you have no idea!