Unless you are writing a police report or a scientific article, where telling the facts is of paramount importance, I fail to see the benefit or purpose of such a description.
If the weighting of the object is the central point of the narration, then there is no need to tell it to the reader; in fact by this point it should be clear that she needs to weigh the object.
On the other hand, if the weighting is not the central point of the narration, then don't mention it. Breaking the narration to insert an action like the one you intend to use is equivalent to a Cechov's gun: it needs to serve a purpose that could not be guessed otherwise from the rest of the story. The important point with a Cechov's gun is that you don't need to tell its purpose: you are going to show it later.
To give an example of the latter point: Jane is at home, talking to her brother, and she is playing with the stone, checking the weight... suddenly she is at the window and throws the stone as far as she can. It is surprising, but foreshadowed. Your description is the foreshadowing. In contrast, if she has been talking to her brother about the stone, and how heavy it is, then you could just rely on the dialogue and remove the description altogether. If you really have to place the description, keep it short, and refrain from explaining the purpose of it:
The stone felt heavy in her hand.
Dropping it would have made a good dent on the metal tray.
Her forearm was bulging and shaking while she held the stone in front of her.
She kept flipping the stone in her palm.