relic castle
A black Onix is a shiny Pokemon, which is extremely rare.
yes when you go find one of the sages at relic castle when you are almost where ghetsis is you can battle onix and sandslash. after you find ghetsis you can also fight volcarona
There is no such thing as a Crystal Onix in the Pokemon games series. It was only in the Pokemon anime.
You can find an Onix in Dark Cave or in Victory Road in the main game.
It can be found in the Relic Castle in Pokemon Black Or White
yes it evoles by happiness
rock tunnel
Onix can be found on seven island, six island and rock tunnel.
It's mainly luck if you find a shiny Pokemon in Black. I was lucky and found a shiny Onix (yay) in Pokemon Platinum, but it's really rare. You're more likely to have your Pokemon get Pokerus (long story) than you are to find a shiny Pokemon. my best advice is to just go out and search grass like crazy. and FYI, i had played my Platinum game for more than 200 hours before i found the onix. ~Akiza
You find it in Orbegugh Mnes or on Iron Island
Rock tunnel, Six island.
In Pokemon Yellow Onix does not evolve, it is a one stage Pokemon.