Islamic brass planter / insence burner ?

I've recently aquired this beautiful brass, what I thought was a plant pot, but after some research I thought it might not be, any info would be greatly appreciated.

It looks to me to be enamelled black and small hints of red, Hand etched.

There is a small heart shape marking on the bottom of it but no idea if it has any significance

Size is

22cm in height
15.5cm in diameter