Peaberry Coffee bean... the 'only child'

Peaberry Coffee bean... the 'only child'

From quora.com

Coffee bean develops in the fruit... which is like a cherry. Usually there is are 2 beans inside the fruit. Hence these seeds have a flattened side (where the seeds are in contact with each other) and a curved side.  However, in 5% of the fruits, only 1 bean develops and hence the seed is less flat and rounder. It is supposed to be denser and smaller and the taste is supposed to be sweeter and more flavourful. This is called the Peaberry Coffee bean and is sold separately as the work involved in harvesting it is much more.

https://procaffeination.com/the-many-types-of-coffee-beans/