Hi Irene,
It could also be Green and Gold (p. 70 in Brown's book). The leaves of Green and Gold are a bit larger than the leaves of Chrysophyllum and are fuller near the petiole.
oh... Green n Gold.... Monday i will double confirm whether that is chrysophyllum or Green n gold.. cause i have had a Green n Gold in my collection. I will use that to compare with this.. (How i wish this is chrysophyllum~~~cause that will add another cv. in my collection!!)