Is the magma in one volcano different from the magma in every other volcano?

Question

First off, a confession: I'm asking this question because of *The Lord of the Rings*. If you're not aware already, in the story, a magical ring can only be destroyed in a specific volcano. The reason for this is presumably "because magic". But the issue got me wondering if this volcano is any different from every other volcano on the planet. Is there a significant difference between the magma in different volcanoes? If so, why? Doesn't all magma come from the same place if you go down deep enough?

Answer 1

"The Lord of the Rings" uses the idea of the unique volcano to build suspense in the movie plot and the basis for all of the travails that the characters must overcome so that the ring can be destroyed.

The physical and chemical (% of different elements, associated gases, rate of cooling, etc.) properties of magma from all volcanoes are different, but may be similar. No, all magma does not come from the same place, but the processes that form the different types are simlar, as are the temperature and pressure range required to generate magma. Pick up a physical geology book or search on line to understand these.