Find the four flames that still burn in those ruins: Samha, Imbel, Byltan, and Lahassa. Retrieve their essence and then while standing by the Equinex Monolith, use the essences to energize the stave. If this is truly is the Stave of Equinex, you will be able to unlock the Monolith and gather a sacred artifact from it.
The Equinex Monolith stands silently among the ruins. What could it be holding?
Holding the energized stave is almost impossible. Its power rumbles through your body.
You reach out to the cold surface of the Equinex Monolith...
A small door opens, allowing you to reach in and take the artifact inside.
Beams of light fill the area around the Equinex Monolith.
Upon completion of this quest you will gain:
The sparkling stone you get from the monolith is a quest item, true, but it is one you get from this quest, and turn in for the following quest. The following quest doesn't give it to you, so you should not 'accidentally' destroy it, as dropping and re-taking the follow-up quest is not likely to give it to you again.
Note that though it's not made known in Quest Helper (as of Version 0.85), you must recover the four flames' essences. They are located in Feralas, Ruins of Ravenwind, at [37.8, 12.2] (Lahassa), [40.5, 12.7] (Samha - have to climb for this one), [39.9, 9.4] (Imbel), and [38.5, 15.8] (Byltan) - conveniently located immediately around the Equinex Monolith [38.9, 13.2]. Some creative jumping will be required to retrieve Samha.