The vase is one piece!
With ceramic, or in this case terracotta, they often ‘glaze’ (part of) the vase (or other object).
So they first bake the clay model and then put on a thin layer of ‘glazing’ fluid and bake it again.
I don’t know how this works exactly, but you can see that the ‘glazed’ part of the vase is more shiny than the rest.
In CG this will be a shading (material) thing. Do not make the vase into two parts!
Your vase looks really good, btw 🙂
