Amany, typically the plant that is called "rubber plant" is a ficus elastica, although I have heard the peperomia called that too.

the care of the peperomia is pretty close to that of your sanseveria (snake plant), although i wouldn't let the peperomia dry out quite as much. do you have a solid leaf or a varigated one?

Thanks for your help. It's the variegate type. It's leaves are just beautiful.

I have a peperomia obtusifolia as well, although not with variegated leaves.
I let mine dry slightly between waterings, but as far as I've learned it is not a succulent proper. Additionally, half a year ago I didn't even know what mine was, and I was likely over watering it and then not watering enough. There was no change - it is very tolerant.
I find that they make great cuttings. I was given my original "baby rubber plant" (not to be confused with a rubber plant, because they are not related) by my aunt, and the first time one of its branches fell off (from a cat playing too close) I immersed it in water. It rooted very easily.
Now I start cuttings all the time (when "baby" need some grooming) and give them to friends. They are very easy to care for and look gorgeous.
I should watch for a variegated leaf variety. I would love to have more of these.