Source: Lost Treasures, pg(s). 40
Lorestones are vast magical repositories of druidic knowledge embedded in small stones. Although different varieties of lorestones are known to exist, all share certain features in common: they are engraved with astronomical objects such as constellations and other celestial objects. Studying lorestones provides information on natural phenomena such as weather patterns and seasonal changes, but can also unlock a deeper truth. Those who unlock these truths gain access to the lorestone's true powers hidden within.
The three known lorestones are the granite sphere (formerly owned by the druid Hemzel in the Verduran Forest, but currently held by the Pathfinder Society in Andoran), the gravetaker sphere (located somewhere within the territory of a fiendish quickwood east of the city of Wispil in Taldor), and the piscine stone (in the possession of a pack of ratfolk in the River Kingdoms).