The official GemStone IV encyclopedia.
The corestone seems to be a natural formation of metal, seemingly gold and silver, which is similar to that of a flower. Because the corestone does not seem to be based on a real life equivalent, and the description includes references to both metallic and crystalline aspects, it is difficult to discern exactly what it is like.
List of Corestones
a piece of corestone
| Description: Brassy in hue with streaks of silver and gold, the corestone is akin to a metal flower blooming with rough, uneven petals. Its luster is brilliant, magnified by the plethora of facets that adorn its crystalline facade.