Guys, look. Rock, Steel, and Ground types are based on different PROPERTIES of the same material. As with all the types, the types are not based on science - they are based on different ideas of these things. Ground actually IS based on the ground we walk on, and it is separate because it is traditionally viewed as fundamentally different from rocks that we throw (which is what the Rock type is based on) because it is less dense. Steel has incredibly different properties from unseparated rock, as it is harder, easier to work, and stronger.
Okay, first of all: I am cool with steel being a separate type. Steel gives a great venue for game freak to design a whole bunch of man-made/robot-themed pokemon like magnezone and pawniard and metagross. Like, there's actually a whole theme missing to pokemon without the steel type; conceptually steel is a pretty neat type. Steel (which is kind of representative of 'metal', not necessarily just steel) has a whole bunch of cultural associations to draw from to make pokemon with - robots, ancient tools, knights, magnets, weapons - all kinds of stuff.
But the fact is, even game freak can't seem to decide what the different ideas of rock and ground actually mean. Out of the pure rock pokemon, probably only the roggenrola line are based from 'rocks we throw at things'* - cranidos is rock because fossil=rock in the pokemon world (which is inconsistent in itself as I've pointed out already), and then there's regirock, which I've already discussed. In fact, going down through all the rock-type pokemon, only a handful are based on actual rocks - and most of them are the traditional gen-1 rock-types (which, again, are rock-ground because there were no rock-types to start with). I mean, look at Crustle - it could easily be a ground-type (apparently it's hermit crab +
stratum). Corsola is coral and a water/rock type, even though coral isn't a rock (it's an animal). The hard part of coral is the skeleton part (made from calcium carbonate and things) but wait no bones are apparently ground type because cubone and marowak and bone rush.
Also, lots of rocks aren't hard! Grab a sedimentary rock like limestone and you can probably break it up yourself pretty easily (you can scratch it with your fingernail and make sand).
Not going to go into how sudowoodo is an exception because. It's sudowoodo. Look at that guy. It can do whatever the hell it wants.
Let's look at ground types! sup groudon representing the lithosphere but inexplicably a ground-type, how's it going! Golett doesn't seem to make any sense - it's the automaton pokemon, which are ancient self-running machines, usually used to describe ancient robots and things, which I would think to be closer to steel than ground - but then bulbapedia also says that it's a golem (nevermind that golem means a bunch of things in pokemon apparently, which I've mentioned already). Yet none of these things represent 'the ground' in any way, really. Then you've got all the pokemon that represent sand - but wait game freak, sandstorm is rock type! More on that in a second. Then there's rhyperior, which seems to just be rock/ground purely because rhyhorn and rhydon are, even though it's covered in ~rocky~ armor. (the protector itself has the description "A protective item of some sort. It is extremely stiff and heavy. It is loved by a certain Pokémon." That sounds a lot like what you guys are saying rocks are - hard, dense stuff!)
Not going to go into gligar because. Look at it.
it can do whatever it wants Seems like game freak wanted to play with types and make a flying/ground pokemon.
as for the typing of the moves, in general, moves are typed in association with different pokemon. Sandstorm is Rock type because it was associated with Tyranitar when it was made. Head Smash is the pseudo-signature move of Rampardos, and it is only learned by rock types.
Okay, that would make sense if:
a) sandstorm only affected rock-types
b) sandstorm were an offensive move that tyranitar could take stab from
c) if it were actually the signature move of tyranitar when it was released (hello sandshrew, onix, and all the pokemon that learn it by TM in gen 2)
But it is none of these! you can't go 'oh, well ground
is sand' and then have sandstorm be a rock move. That either establishes that sand is pretty much the same thing in the pokemon world as rock (and the whole world is inconsistent) or that game freak just decided to make rock and ground a pretty arbitrary divide. Power Gem is learnt by all kinds of pokemon that aren't rock types, rollout is given to anything round (apparently), spikes is a ground type... because why? o.o spikes made out of sand or mud or whatever is going to be pretty useless as far as spikes go, unless they're hard like rocks or someth-- oh wait. It's also not learned by
any ground types (cheers zhorken for that one).
spike cannon is also a normal type, so apparently spikes are basically anything game freak wants them to be nevermind that only holds true in english.
Anyway my point even is that it conceptually the types are so similar to each other that it really seems like game freak separated them arbitrarily for the type chart. I'm not going to argue with that decision because game freak are great and I love them, but I really think that's what's going on. Water and ice have such separate cultural meanings that there are lots of legends to draw from to make pokemon out of. This is not the same for rock and ground!
Anyways, there's my two cents. can we stop fighting about the way a game was coded now?
?_? who's fighting? I'm just interested in discussing it. If you're finding it so inflammatory then it's not like you have to participate.
*also game freak finally seemed to realise 'oh hey, gems are rock, right? neat' bless them