Gosa Gosa no Mi

Appearance
The fruit appearance is that of a simple black apple with white spirals.

Powers
The fruit bestows upon the user the ability to accurately measure the mass and by logical extension and simple calculations the energy and weight of any given object physical or hypothetical by creation of a new organ in their cheek that looks much like a pupil-ess eye.

Usage
The fruit's main use is mostly parlor tricks in that the user would be able to accurately tell how much mass of a given something would exist in a given object or space.

It also allows for the user to accurately weight everything he so desires without ever needing a tool, and thus the fruit is very useful for a variety of professions but mostly for chemists who can use this ability to create reactions work in ways most beneficial for them and weight the results.

But the most interesting ability is how the user can make hypothetical assumptions of some object or entity and will be able to accurately tell the mass of such thing, even of the individual components. With this last ability the user can imagine a specific chemical of specific properties and if it is possible to be achieved he will be allowed to know by the fruit of the specific components and the mass of them.

This fruit interestingly enough is one the few with little to no practical use by a normal person and has absolutely no destructive power to it, but it is famed in the chemistry world by use of ??? and the various breakthroughs he did.

Weakness
The user suffers from the standard devil fruit weakness, except the user cannot measure kairoseki, and upon trying to a blank will simply appear in his mind, however he is able to tell if it is inside a given object simply not the quantity.