The planet, due to its proximity to the sun, had a very dense, spherical core consisting of gold-platinum alloys and other pure ores. The upper mantle was a shallow layer of liquid mercury, which reflected much of the sun's light.The planet's continental plates were constantly shifting atop an underground sea of mercury, sometimes up to 630 km a day. There were 18 continent-sized land-masses on the surface of the planet, which constantly tore away pieces of each other; though they constantly re-grew through rapid crystal growth on the underside. Numerous smaller islands drifted between the continents, but rarely survived very long.
Compared to the sea, the continents were relatively light, consisting of cinnabar, sulfite, and manganese compounds and plain rock, which gave them a color pattern of red, orange, purple and gray. Due to the constant shifting of the continents and a high gravity, the terrain was flat with no hills.
The atmosphere was relatively thin but was stable with airborne nitrogen and sulfur compounds precipitating excessive mercury that boiled up in small explosions. The thin atmosphere caused storms that appeared in average strength and numbers.
When the Yavin system was surveyed during the Galactic Expansion era, Fiddanl was charted as 96NK3F2. Two passes were made, but none found anything interesting except for the rapid crystal growth beneath the planet's continents.
Since the planet was toxic to almost all lifeforms, far away from major trade routes and had little important resources, there had been no interests in starting a mining operation.
- Galaxy Guide 2: Yavin and Bespin
- Galaxy Guide 2: Yavin and Bespin, Second Edition
- The Complete Star Wars Encyclopedia
- The Essential Atlas