Words of magic

Sorry, couldn't think of a better place to put this...
Since magic is kind of a science in the setting I'm working on, I need to categorise stuff a bit, and I'm running into some problems because I can't figure out what some english words mean exactly.

"Spell" seems clear enough - but is there a word that can be used without problem for an act of magic that does NOT involve incantations/spoken words?
"Charm" makes me think more of amulets...

What's the difference between "hex", "curse" and "jinx" exactly?

Any help, or significant vocabulary I forgot?

Good questions all, and I don't know the answers for definite. Fantasy and modern paganism both have hugely differing opinions, so these are only my own interpretations.

In Harry Potter terms, a charm is generally a spell/thingy with positive effects. But there's also "charm" in the sense of charming someone, like magically getting them to like you or controlling them.

Jinxes usually seem to be to do with bad luck, and perhaps don't have to be deliberately cast - people use the word 'jinxed' to describe someone who's seemingly naturally clumsy and unlucky.

I don't know how you'd distinguish between a hex and a curse, except I suppose you could argue that only Hexen can cast hexes. *g* Curses, in olden times, weren't spells but more a prayer for something bad to happen to someone - sort of "I hope your legs drop off!" It's closely related to cursing in the sense of using naughty words.

Funnily enough, I made up an organised-ish system of magic for Shade. It works on a semi-scientific basis too.

I made up my own vocabulary for the most part, but I use "spell" to mean a magical process that is learned by heart and cast (by whatever method - speaking, gesturing, hiccupping, dancing etc).