A dental implant healing cap is normally submerged under the gum. mine shows a very small visible cap above the gum.is this called a 1 stage implant?

Yes: Sometimes implants uncover themselves regardless of how deep you place them, but you are correct in calling it a one stage surgery. You may still need some minor refinement of the implant site at the time of the impression, but that's the restorative dentist's decision,

Yes, it is normal: The healing cap looks like a small metal cylinder that sits above your gums. If concerned, see your surgeon/dentist for post-op eval.