Her druidic training lets her recognize the presence of natural ambient magic concentrated in the crystals. She recalls the Underdark has a strong background of magical radiation that pervades its environment, providing a source of power and nourishment for plant life in lieu of the sun's light... among other, more unpredictable effects.<br/><br/>Establishing any further information on the crystals would require a more technical examination of their properties, though it's very likely they are simply "glowy" and appear much more impressive than they actually are.