Please help ID mystery (inedible) fruit

[HI_Chris]

A friend in Hawai'i planted a 'fruit' tree more than 2 decades ago.  It is now an attractive tree about 25' tall and equally wide.  I am told that the fruit is inedible, but I was hoping someone here could point me in the right direction for an identification.  The larger of the two fruits is 4" across and is a bit less from bottom to top.

Photos below.

Many thanks in advance for your help here,
Chris

[Mike T]

Black sapote and you received bad advice on edibility,

[fruitlovers]

Black sapote is edible, but the fruits in your photo are not ripe yet. They need to get nice and soft to be ripe, and ready to eat.

[HI_Chris]

Thanks Mike and Oscar!!

Knowing what it is will help tremendously in figuring out how to eat it.  Somehow my friend thought he had planted a mangosteen, but when I saw the leaves they weren't paired (like the 3 kinds of mangosteens I have growing) I had my doubts.

I very much appreciate your ID help,

Best,
Chris