Doesn't look like it to me, there are numerous species of Gymno.
I would imagine you'd be able to cross pollinate two Gymnos, but I don't know a lot about cross-pollinating cacti.
The moon cacti you see in the stores are unnatural (yellow, orange, red, pink). They are man made and unable to produce their own chlorophyl (plant food), hence being grafted to a green stalk. If you're lucky, sometimes you find a purple one that isn't man made grafted and you can remove it from the stalk and root it (you can't do this with the others, they won't survive). I'm not sure what species of Gymno the purple ones are, I think G. mihanovichii (but not sure which cultivar).
But the original green moon cactus? I didn't know there was one, but then again, I'm no expert on Gymnos. Where did you read about the original one? I am just curious as you've got me interested now.
Planto
